Utrecht, April 2013
Redesign of the Maintenance Concept Development Framework for Heineken, with an application on the Packers of Production Line 7 at Heineken Zoeterwoude by Merel de Bruijn
BSc Industrial Engineering & Management Science for Healthcare (2010) Student Identity Number 0616953
in partial fulfilment of the requirements for the degree of Master of Science in Operations Management and Logistics
Supervisors: Ing. D.J.N. Ypenburg MSc, Rayon manager Packaging, Heineken Zoeterwoude B. de Winter-Bal MBA, Rayon manager Technology, Heineken Zoeterwoude Ir. dr. S.D.P. Flapper, Eindhoven University of Technology, OPAC Dr. H. Peng, Eindhoven University of Technology, OPAC
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TUE. School of Industrial Engineering. Series Master Theses Operations Management and Logistics
Subject headings: Maintenance optimisation, Maintenance costs, Availability.
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ABSTRACT In this master thesis, the maintenance concept review and improvement process of Heineken is redesigned. Firstly, a feedback loop is proposed to realize continuous improvement of the maintenance concepts. Additionally, the current framework of Heineken that prescribes how to develop/improve a maintenance concept is redesigned, based on a literature review and experience at Heineken Zoeterwoude. The redesigned framework includes more possible maintenance policies that can be applied at a component and a redesigned method that determines which maintenance policy to apply on which component. Furthermore, the redesigned maintenance concept development framework is applied on the packers of production line 7 of Heineken Zoeterwoude. The developed maintenance concept reduces the breakdown time caused by breakdowns of the packers and fulfills the determined availability target of the technical systems, with minimal costs. Finally, recommendations regarding the use of the redesigned framework and further improvements of the maintenance organization at Heineken Zoeterwoude are provided.
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PREFACE & ACKNOWLEDGEMENT This master thesis report is the result of the last phase in the master Operations Management & Logistics at Eindhoven University of Technology. This research project is carried out at Heineken Zouterwoude, lasted from September 2012 till March 2013. I have conducted a challenging project at Heineken, which was a great experience! This would not have been possible without some of you, for which some thanks are in place. Firstly, I would like to thank my mentor and first supervisor from the university, Ir.dr. S.D.P. Flapper. I appreciate his advice and the critical remarks he made about my report. It helped me stay critical towards my research and thesis and further improve its quality. I enjoyed the pleasant conversations we had and am grateful for all the time and effort he put into my research. Furthermore, I would like to thank my second supervisor from university, Dr. H. Peng, for her time and the questions she could ask to which helped me to improve my thesis. My thanks go also to Dirk Ypenburg, my supervisor at Heineken. I have really enjoyed working together and I learned a lot from him. His guidance and support for my project motivated me to strive for good and renewing results at Heineken. Additionally, I would like to thank Belinda de Winter, my second supervisor from Heineken, for her advice during my internship. I would also like to thank all my colleagues at Heineken Zoeterwoude that made my internship to such an incredible experience. Finally, I would like to thank my family and friends for their love and support during my entire study. Special thanks are in place for my boyfriend Geert, for his believes in me and his incredible encouragement.
Merel de Bruijn Utrecht, April 2013
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EXECUTIVE SUMMARY This master thesis report is the result of the last phase in the master Operations Management & Logistics at the Eindhoven University of Technology.
INTRODUCTION This research is executed at Heineken Zoeterwoude, one of the breweries of Heineken International. It is the largest beer brewery of Europe, in terms of brewed hectoliters. It brews Heineken, Amstel and Sol for the national as well as the international market and packs it in cans, bottles and vessels. The beer is brewed in the Brewery department and packed by the Packaging department which consists of 13 production lines. The research area of this project is the technical system ‘the packer’ of production line 7. This production line does not reach its performance target (defined as OPI-Nona) from April until August 2012. Heineken already started several initiatives to investigate different aspects of the low performance. This project will focus on the high breakdown time of the packers, by improving the maintenance concept of the technical systems. A maintenance concept is a collection of rules that describe maintenance: what maintenance tasks are required, when the tasks should be performed, how each task should be performed (criteria) and who should perform the maintenance task.
REDESIGNED MAINTENANCE CONCEPT DEVELOPMENT FRAMEWORK In order to be able to develop a new maintenance concept that will fulfill the objective of having unplanned downtime and thereby reaching the performance target (in OPI-Nona) of production line 7 within a certain budget, the general procedures and methods of Heineken to develop a maintenance concept are investigated and improved if required. Phase 1 Preparation maintenance concept development
Phase 2 Development maintenance concept
Phase 3 Evaluation developed maintenance concept
Set objectives and restrictions
Color breakdowns in ISO-metric
Evaluate costs of determined tasks (€ PM < € breakdown)
Gather information technical system
Color maintenance activities in machines ISO-metric
Evaluate required time and spare parts for tasks
Gather current maintenance concept
Determine relevant maintenance policies for technical system
Evaluate objectives and restrictions
Gather data breakdowns of the last year
Determine / evaluate maintenance policy and tasks
Ask permission for adjustments
Gather data breakdowns longer than 1 year ago
Determine possible maintenance policies per MSC
Adjust documents of the maintenance concept
Verify the gathered data
Determine optimal policy parameter values
Gather data of breakdowns of similar technical systems
Check implementation in all documents
Determine maintenance concept
Gather data spare components
Determine required spare components
Determine Maintenance Significant Components (MSC)
Cluster / harmonize maintenance activities
Phases framework
Replaced steps
Added steps
Changed content
Group maintenance activities
FIGURE 1: REDESIGNED MAINTENANCE CONCEPT DEVELOPMENT FRAMEWORK
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Removed steps
Original MO-steps
The current Maintenance Optimization method of Heineken is compared to several maintenance concept development frameworks from literature. Based on a literature review, knowledge and experience at Heineken, the Maintenance Optimization method of Heineken has been redesigned. The adjustments of Heinekens framework in order to develop the redesigned framework are shown in Figure 1. It can be seen that several steps of the original Maintenance Optimization framework of Heineken will remain the same, others are removed or their content is changed. Some new steps are added. The framework as shown in Figure 1 is divided in three phases (blue boxes): (1) the preparation phase, (2) the development phase and (3) the evaluation phase. The goal of the first phase is to gather all required information and data to develop a maintenance concept. Compared to the original Maintenance Optimization framework of Heineken, data of additional sources is gathered and specific objectives and restrictions have to be formulated. Additionally, the method of determining which components of the technical system should be included in the maintenance concept is redesigned. In the second phase, te development phase, the maintenance concept is developed. In the redesigned framework as shown in Figure 1, more maintenance policies are taken into account. Thereby, the method of determining which maintenance policy to apply at a component is redesigned. The maintenance concept developed according to this framework will include the technically feasible maintenance policy for each Maintenance Significant Component with the lowest costs. Additionally, the Greedy heuristic is presented which can be applied if the objectives for the maintenance concept are not directly met. In the third phase, the evaluation of the developed maintenance concept is changed. The two evaluation steps of the original framework of Heineken are removed and a new evaluation step is added. The steps in this phase regarding the implementation of the framework will remain in the redesign. Besides the redesigned framework on how to develop a maintenance concept, a feedback loop is proposed that will continuously improve a maintenance concept (shown in Figure 2). Every 2 years or in case of too high breakdown times in 3 succeeding months, the maintenance concept should be reviewed and improved.
FIGURE 2: TRIGGER START MAINTENANCE CONCEPT IMPROVEMENT
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APPLICATION OF THE REDESIGNED FRAMEWORK The redesigned framework as presented in this research is applied at the packers of production line 7. Unfortunately, at the moment there is not enough reliable data available at Heineken to determine e.g. the Time to Failure distribution of a component (which provides an estimation of the life time of a component), the replacement time and unplanned downtime in case of a breakdown. Therefore, the maintenance experts estimated the required input, based on their knowledge and experience. A maintenance concept for the packers is developed according the steps of the redesigned framework. This results in a maintenance concept with in total 138.475 minutes of breakdown time for both packers together during 10 years, equalling 575 minutes breakdown time per month per packer. Breakdown time is defined as unplanned downtime, lasting 5 minutes or longer. The expected breakdown time of the new maintenance concept is 5 minutes above the set objective of a maximum acceptable expected breakdown time of 138.480 minutes. While at the moment, using the current maintenance concept, the breakdown time is expected to be about 700 minutes per packer per month, based on the breakdowntime of June till August 2012. Since breakdown data of that period is not reliable, this number is based on estimation. Executing the maintenance activities when the newly developed maintenance concept is applied will cost €964.310,80 for both packers during 10 years, meaning a budget saving of €35.689,20, whereas the costs of maintenance of the packers from January till August 2012 were already above €100.000,-.
CONCLUSIONS & RECOMMENDATIONS The goal of this research is to increase the performance (measured as OPI-Nona) of production line 7, through reduction of the breakdowns of the packers by the development of a new maintenance concept. Although the OPINona of a production line is influenced by many factors, a required OPI-Nona increase is estimated and used as objective. The maintenance concept for the packers developed in this research satisfies the maximal acceptable expected breakdown time and can be executed within the determined maintenance budget. There are several recommendations for Heineken to further improve maintenance:
Implement a feedback systems that triggers the review and improvement of current maintenance concepts to create dynamic maintenance concepts that are continuously improved. Apply the redesigned maintenance concept development framework with the steps explained in this research. Improve the data registration via SAP to gather more accurate and reliable data that can be used to estimate e.g. the life time distributions of components, the replacement time and the unplanned downtime in case of a breakdown. Link the production data to SAP, to establish maintenance concepts based on production time instead of calendar time. This is especially relevant in case of varying production hours per week (like the change between 3 shifts and 5 shifts) and technical systems that do not always produce when the line is operating (like the six-pack systems of line 7). Apply a maintenance activity type at each component, which prescribes what maintenance activity should be executed (e.g. a replacement, a perfect repair of the component or a minimal repair). Investigate the current stock of spare components and use the influence of spares in the decision of maintenance policies and the development of the maintenance concept.
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TABLE OF CONTENTS Abstract ........................................................................................................................................................................ V Preface & acknowledgement...................................................................................................................................... VII Executive summary .......................................................................................................................................................IX Introduction ..............................................................................................................................................................IX Redesigned maintenance concept development framework ..................................................................................IX Application of the redesigned framework ................................................................................................................XI Conclusions & Recommendations ............................................................................................................................XI 1.
2.
3.
4.
5.
Introduction ...........................................................................................................................................................1 1.1.
Heineken Zoeterwoude ................................................................................................................................1
1.2.
Lay-out production line 7 .............................................................................................................................1
1.3.
Problem introduction ...................................................................................................................................2
1.4.
Chapter summary .........................................................................................................................................3
Analysis of the problem statement .......................................................................................................................4 2.1.
Determining research area ..........................................................................................................................4
2.2.
Current maintenance concept packers ........................................................................................................5
2.3.
Cost of maintenance ....................................................................................................................................6
2.4.
Chapter summary .........................................................................................................................................6
Research design .....................................................................................................................................................7 3.1.
Research goal ...............................................................................................................................................7
3.2.
Research questions ......................................................................................................................................7
3.3.
Research restrictions ....................................................................................................................................8
3.4.
Research deliverables ..................................................................................................................................8
3.5.
Report outline ..............................................................................................................................................8
3.6.
Chapter summary .......................................................................................................................................10
Establishment of dynamic maintenance concepts ..............................................................................................11 4.1.
Current trigger for maintenance concept improvement at Heineken .......................................................11
4.2.
Trigger for maintenance concept improvement from literature ...............................................................11
4.3.
New trigger for maintenance concept improvement for Heineken ..........................................................12
4.4.
Chapter summary .......................................................................................................................................12
Framework for the development of a maintenance concept ..............................................................................13 5.1.
General phases in the maintenance concept development framework ....................................................13
5.2.
Explanation ´Maintenance Optimization´ Framework Heineken ...............................................................13
5.3.
Confrontation MO framework with frameworks from literature ..............................................................14 XIII
5.3.1.
Overview literature maintenance concept development frameworks .................................................14
5.3.2.
Confrontation phase 1: Preparation ......................................................................................................15
5.3.3.
Confrontation phase 2: Development ...................................................................................................16
5.3.4.
Confrontation phase 3: Evaluation ........................................................................................................16
5.4. 5.4.1.
Construction of the redesigned framework ..........................................................................................16
5.4.2.
Content of the redesigned framework ..................................................................................................17
5.5. 6.
7.
8.
Redesign framework ..................................................................................................................................16
Chapter summary .......................................................................................................................................19
Content of the step ‘Determine MSCs’ ................................................................................................................20 6.1.
Explanation Criticality matrix of Heineken .................................................................................................20
6.2.
Confrontation of the criticality matrix of Heineken with literature ...........................................................20
6.3.
Redesign of the criticality matrix ...............................................................................................................21
6.4.
Execution of the step ‘Determine MSCs’ ...................................................................................................21
6.5.
Chapter Summary ......................................................................................................................................21
Content of the step ‘Determine relevant maintenance policies’ ........................................................................22 7.1.
Maintenance policies currently used at Heineken .....................................................................................22
7.2.
Overview maintenance policies from literature ........................................................................................22
7.2.1.
Corrective Maintenance ........................................................................................................................23
7.2.2.
Time Based Maintenance ......................................................................................................................23
7.2.3.
Condition Based Maintenance ...............................................................................................................24
7.2.4.
Predictive Maintenance .........................................................................................................................24
7.2.5.
Remarks on the constructed overview of maintenance policies ...........................................................25
7.2.6.
Maintenance activity type .....................................................................................................................25
7.3.
Confrontation maintenance policies Heineken with literature .................................................................26
7.4.
Redesign new maintenance policies and maintenance activity types .......................................................27
7.4.1.
Benefits of the overview of maintenance policies.................................................................................27
7.4.2.
Benefits of the overview of the maintenance activity types .................................................................27
7.4.3.
Risks of the redesigned method ............................................................................................................27
7.5.
Execution of ‘Determine relevant maintenance policies’ ..........................................................................28
7.6.
Chapter summary .......................................................................................................................................28
Content of the step ‘Determine possible maintenance policies’ ........................................................................29 8.1.
Explanation of the maintenance policy decision tree of Heineken............................................................29
8.2.
Confrontation maintenance policy decision tool with literature ...............................................................30
8.2.1.
Modification...........................................................................................................................................30 XIV
8.2.2.
Failure rate .............................................................................................................................................30
8.2.3.
Time to Failure distribution ...................................................................................................................31
8.2.4.
Shortcomings of the maintenance policy decision tree of Heineken ....................................................31
8.3.
Redesign of the maintenance policy decision tree ....................................................................................32
8.4.
Execution of ‘Determine possible maintenance policies’ ..........................................................................33
8.4.1.
Substep A: Develop a maintenance policies possibilities tree ...............................................................33
8.4.2.
Substep B: Accomplish the tree for each MSC.......................................................................................33
8.5. 9.
Chapter summary .......................................................................................................................................33
Content of the step ‘Determine optimal policy parameter values’ .....................................................................34 9.1.
Current method of determining optimal parameter values Heineken ......................................................34
9.2.
Confrontation method of Heineken with literature ...................................................................................34
9.2.1.
Number of expected replacements .......................................................................................................34
9.2.2.
Probability of missing deterioration ......................................................................................................34
9.3.
Redesigned method of determining optimal parameter values ................................................................35
9.4.
Execution of ‘Determine optimal policy parameter values’.......................................................................35
9.4.1.
Substep A: Develop TMC calculations....................................................................................................35
9.4.2.
Substep B: Gather required input for the TMC calculations ..................................................................36
9.4.3.
Substep C: Determine optimal policy parameter value .........................................................................37
9.5. 10.
Chapter summary .......................................................................................................................................37 Content of the step ‘Determine maintenance concept’ .................................................................................38
10.1.
Substep A: Determine maintenance policy per MSC .................................................................................38
10.2.
Substep B: Check objectives .......................................................................................................................38
10.2.1.
Total Maintenance Cost of the developed maintenance concept ....................................................38
10.2.2.
Direct maintenance cost related to the maintenance concept .........................................................38
10.2.3.
Expected unplanned downtime related to the maintenance concept ..............................................38
10.2.4.
Check objectives of the maintenance concept ..................................................................................39
10.3.
Substep C: Improve initial solution according objectives ..........................................................................39
10.3.1.
Explanation Greedy heuristic ............................................................................................................39
10.3.2.
Example Greedy heuristic ..................................................................................................................40
10.4. 11.
Chapter summary .......................................................................................................................................40 Execution Phase 1 of the redesigned framework to the packers ...................................................................41
11.1.
Set objectives and restrictions ...................................................................................................................41
11.1.1.
Objectives ..........................................................................................................................................41
11.1.2.
Restrictions ........................................................................................................................................42 XV
11.2.
Gather information technical system.........................................................................................................43
11.3.
Gather information of the current maintenance concept .........................................................................43
11.4.
Gather data of breakdowns .......................................................................................................................43
11.5.
Verify the gathered data ............................................................................................................................43
11.6.
Gather data of breakdowns of similar technical systems ..........................................................................44
11.7.
Gather data spare components .................................................................................................................44
11.8.
Determine Maintenance Significant Components .....................................................................................45
11.9.
Chapter summary .......................................................................................................................................45
12.
Execution Phase 2 of the redesigned framework for the packers ..................................................................46
12.1.
Colour breakdowns in ISO-metric ..............................................................................................................46
12.2.
Determine relevant maintenance policies for the technical system .........................................................46
12.2.1.
Maintenance policies taken into account for the packers ................................................................46
12.2.2.
Maintenance policies not taken into account for the packers ..........................................................46
12.3.
Determine possible maintenance policies per MSC ...................................................................................47
12.3.1.
Step A: Maintenance policy possibilities tree packers line 7.............................................................48
12.3.2.
Step B: Go through the tree for each MSC ........................................................................................48
12.4.
Determine optimal policy parameter values .............................................................................................49
12.4.1.
Step A: Develop TMC formulas for all relevant policies ....................................................................49
12.4.2.
Step B: Gather required input for the TMC calculations ...................................................................50
12.4.3.
Step C: Optimal policy parameter value of possible maintenance policies ......................................52
12.5.
Determine maintenance concept ..............................................................................................................53
12.5.1.
Substep A: Determine maintenance policy per MSC ........................................................................53
12.5.2.
Substep B: Check objectives ..............................................................................................................54
12.5.3.
Substep C: Improve initial solution according objectives ..................................................................54
12.6.
Determine required spare components .....................................................................................................55
12.7.
Cluster / harmonize maintenance activities ..............................................................................................55
12.8.
Group maintenance activities ....................................................................................................................58
12.9.
Chapter summary .......................................................................................................................................58
13.
Execution phase 3 of the redesigned framework for the packers ..................................................................59
13.1.
Evaluate objectives and restrictions ..........................................................................................................59
13.1.1.
Evaluate objectives ............................................................................................................................59
13.1.2.
Evaluate restrictions ..........................................................................................................................59
13.2.
Ask permission for adjustments .................................................................................................................59
13.3.
Adjust documents of the maintenane concept ..........................................................................................59 XVI
13.4.
Check implementation in all documents....................................................................................................59
13.5.
Chapter summary .......................................................................................................................................59
14.
Conclusions and recommendations ...............................................................................................................60
14.1.
Conclusions ................................................................................................................................................60
14.2.
Recommendations .....................................................................................................................................62
14.2.1.
Implement continuous improvement and the redesigned framework .............................................62
14.2.2.
Review current maintenance concepts .............................................................................................62
14.2.3.
Improve data registration via SAP .....................................................................................................62
14.2.4.
Maintenance concepts based on production time ...........................................................................63
14.2.5.
Maintenance activity type combined with a maintenance policy .....................................................63
14.2.6.
Analyzing required spares in stock ....................................................................................................63
14.3.
Academic relevance ...................................................................................................................................63
Bibliography .................................................................................................................................................................65 Figures and tables ........................................................................................................................................................67 Figures .....................................................................................................................................................................67 Tables .......................................................................................................................................................................68 APPENDIX A
List of abbreviations ..........................................................................................................................72
APPENDIX B
List of definitions ...............................................................................................................................73
APPENDIX C
Targets Brewery Comparison System ................................................................................................75
APPENDIX D
Literature review maintenance concept frameworks .......................................................................78
D 1.
Maintenance concept development methods ...........................................................................................78
D 1.1.
Total Productive Maintenance ..............................................................................................................78
D 1.2.
Reliability Centered Maintenance .........................................................................................................79
D 1.3.
Maintenance optimization.....................................................................................................................79
D 1.4.
Framework Gits......................................................................................................................................80
D 1.5.
Framework Vanneste & Van Wassenhove .............................................................................................81
D 1.6.
Framework Wayenbergh & Pintelon .....................................................................................................81
D 2.
Review frameworks ....................................................................................................................................82
D 2.1.
Comparison of the frameworks .............................................................................................................82
D 2.2.
Relevance for Heineken .........................................................................................................................83
APPENDIX E
Construction redesigned framework .................................................................................................84
E 1.
Phase 1: Preparation maintenance concept development ........................................................................84
E 2.
Phase 2: Development maintenance concept ...........................................................................................85
E 3.
Phase 3: Evaluation developed maintenance concept ..............................................................................86 XVII
APPENDIX F
Explanation Criticality Analysis ..........................................................................................................87
APPENDIX G
References Maintenance Policies ......................................................................................................89
APPENDIX H
Literature review maintenance policy decision tree .........................................................................90
H 1.
Maintenance policy decision tools .............................................................................................................90
H 1.1.
Decision Making Grid of Labib ...............................................................................................................90
H 1.2.
Maintenance policy decision tree Wayenbergh & Pintelon (2002) .......................................................90
H 1.3.
Maintenance policy decision tree Wayenbergh & Pintelon (2004) .......................................................91
H 1.4.
Maintenance decision logic Rausand ....................................................................................................92
H 1.5.
Maintenance policy determination Tsang .............................................................................................92
H 1.6.
Maintenance policy decision diagram of Stork Maintenance Management .........................................92
APPENDIX I
Schematic lay-out packers line 7 .......................................................................................................95
APPENDIX J
Adjustments breakdown registration ................................................................................................97
APPENDIX K
Maintenance Significant Components (BOM) ...................................................................................98
APPENDIX L
Answers maintenance policy possibilities tree ...............................................................................102
APPENDIX M
Mathematical formulations TMC ....................................................................................................106
M 1.
Input TMC formulas .................................................................................................................................106
M 2.
Total Maintenance Cost per maintenance policy ....................................................................................107
M 2.1.
TMC Corrective Maintenance..........................................................................................................107
M 2.2.
TMC Block policy .............................................................................................................................107
M 2.3.
TMC Age dependent policy .............................................................................................................107
M 2.4.
TMC CBM Periodic inspections ........................................................................................................107
M 2.5.
TMC Predictive maintenance â&#x20AC;&#x201C; periodic measurement ..................................................................108
APPENDIX N
Calculations TMC example components .........................................................................................109
APPENDIX O
TMC all MSCs for possible maintenance policies ............................................................................110
APPENDIX P
Clustering maintenance activities ...................................................................................................114
P 1.
Clustering assembly dozenwip .................................................................................................................114
P 2.
Clustering assembly anti-kantel mechanisme ..........................................................................................114
P 3.
Clustering assembly demptafel ................................................................................................................115
APPENDIX Q
Planning maintenance activities ......................................................................................................116
Q 1.
Planning revision ......................................................................................................................................116
Q 2.
Planning stopday ......................................................................................................................................117
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1. INTRODUCTION This chapter provides an introduction of the problem researched in this thesis. Firstly, the research area is shortly introduced: Heineken Zoeterwoude (section 1.1) and especially production line 7 (section 1.2). Section 1.3 will presents the problem introduction, as given by Heineken. The problem is further analysed in section 1.4, to determine the scope of this research.
1.1.
HEINEKEN ZOETERWOUDE
This research is executed at Heineken Zoeterwoude, one of the breweries of Heineken International. It is the largest beer brewery of Europe, in terms of brewed hectoliters. It brews Heineken, Amstel and Sol for the national as well as the international market and packs the beers in cans, bottles and vessels. The brewery at Zoeterwoude exists of several supporting departments and two production departments: the Brewery, where the beer is brewed, and the Packaging department, where the beer is bottled or canned (organizational chart in Figure 3). The packaging department is divided in 5 different units, called rayons. Each rayon consists of 2 or 3 production lines, specialized in a specific packaging type and serving a specific segment of the market. Heineken Netherlands
Brewery Wijlre
Brewing
Brewery Zoeterwoude
Brewery Den Bosch
Safety, Environment & Health
Packaging
Rayon 1
Rayon 2
Rayon 3
Rayon 4
Rayon 5
Line 9, 11 & 12
Line 21, 22 & 3
Line 51
Line 41, 42 & 6
Line 7, 81 & 82
Technical Department
Maintenance department
Building management
Quality & Technology
Technical storehouse
FIGURE 3: ORGANIZATIONAL CHART HEINEKEN ZOUTERWOUDE
1.2.
LAY-OUT PRODUCTION LINE 7
The research area of this project is production line 7. On this production line, beer is packed in one-way bottles and in cardboard boxes for the international market. Line 7 is divided in 2 different areas: the wet section and the dry section. Figure 4 provides a schematic overview of the construction of line 7, which is explained in the text below. Each box represents a technical system, which is defined as a group of physical components that together fulfill one specific function. Figure 4 is explained below, from the top to the bottom of the figure. In general, the wet section (blue boxes in Figure 4) is responsible for the beer bottles. The empty bottles arrive on pallets at the depalletiser, which puts the bottles on conveyer belts. Then they are filled with beer, closed with crown-caps, pasteurized and lastly they are labeled. Except for the pasteurizer, there are 2 technical systems of each, e.g. Filler 71 & 72 and Labeler 71 & 72. In front of a technical system, the bottles are separated in two lines going into one of the two systems. After that they come together again. When the bottles have been labeled, they are ready to be packed and via a conveyor belt they are transported to the packers at dry section. The dry section (red boxes in Figure 4) is the other workplace of line 7 and is responsible for the construction and filling of the boxes, such that they can be packed on pallets and transported to the customer. At the dry section, there are also 2 technical systems of each, except for the 6-pack setup that has 4 of each. Different 1
from the wet section, the products do not come together after a technical system; from the box setup on, there are 2 separate lines with each a connection to 2 6-pack setups (as shown in Figure 4) .
Box setup 71
Depalletiser 71
Depalletiser 72
Filler 71
Filler 72
Interior setup 71
Pasteurizer
Box setup 72
Interior setup 72 6-Pack setup 721
6-Pack setup 711 6-Pack inserter 71
Labeler 72
Labeler 71
6-Pack setup 712
6-Pack inserter 72 6-Pack setup 722
Packer 71
Packer 72
Box closer 71
Box closer 72
Palletiser 71
Palletiser 72
Wet section Dry section Palletiser
FIGURE 4: SCHEMATIC OVERVIEW LINE 7
At the dry section, flat cardboard boxes are glued together to cardboard boxes through the box setup. After that, depending on the order, an interior for 24 bottles is inserted in the box, or 4 six-pack cartons are inserted. A camera checks if the interior or six-packs are placed correctly and then the box is transported to the packer. At the packer, the bottles and boxes come together and the packer places the 24 bottles in the box. Next, the box is weighted to check if there are enough bottles in the box and the bottles are filled with enough beer. Then the box is closed, the upper side is glued and the box goes to the palletiser (yellow boxes in Figure 4). This is another section, physically outside the hall of rayon 5. Packed boxes of all lines arrive at the palletiser to be packed on pallets and to load them into trucks.
1.3.
PROBLEM INTRODUCTION
The performance of a production line is measured according the Brewery Comparing System (BCS) developed by Heineken, which prescribes performance goals per production line that are used for breweries all over the world. The key performance indicator used by Heineken for a production line is OPI-Nona (Operational Performance Indicator â&#x20AC;&#x201C; No Order No Activity), defined as the percentage time required to produce the produced output of the total time available for production. It can be calculated according formula 1.1: (1.1) Where the theoretical production time is defined as the time theoretically required to produce the produced orders (based on the production norms) and the effective working time is the time there are orders available that should be produced at that moment, according the production schedule. OPI-Nona and other performance indicators of the BCS are defined to prescribe each moment of time to a certain category, with its own targets. A more specified definition of OPI-Nona and the other time targets, the target values and their realizations are explained in APPENDIX C. The problem area of this research is the low performance of production line 7, since it did not reach its OPINona targets for the last six months. Figure 5 shows that the target OPI-Nona of production line 7 equals 67,08% (blue line) and the realized OPI-Nona is below target from April 2012 till August 2012 (the start moment of this research). 2
15000,5 10000,5 5000,5 0,5
FIGURE 5: OPI-NONA TARGET AND PERFORMANCE OF PRODUCTION LINE 7, JAN-AUG 2012
Figure 6 shows the targets and realizations in 2012 for the other performance measures (as mentioned above and explained in APPENDIX C) that do not reach targets. These categories exceed their targets, calculated in percentage of the effective working time, which is (as explained above) the time there are orders available that should be produced at that moment, according the production schedule. However, they are non-producing activities that in reality take more time than planned and therefore, less time is available for production. 17%
Target Planned downtime
15%
Planned downtime
13%
Target Breakdown time
11%
Breakdown time Target Minor stops
9%
Minor stops
7% January February
March
April
May
June
July
August
FIGURE 6: TARGET AND REALIZATION DOWNTIME INDICATORS (IN PERCENTAGE OF TOTAL AVAILABLE TIME), JAN-AUG 2012
As mentioned in APPENDIX C, the planned downtime shown in Figure 6 is scheduled time the line is not producing while personnel is present. Unplanned downtime is defined as time that all resources required for production except the technical system are available; production is not possible due to internal problems. Breakdown time (green line in Figure 6) and minor stops (red line in Figure 6) are the two unplanned downtime categories. If one moment of unplanned downtime takes longer than 5 minutes, it is called breakdown time; an unplanned downtime moment less than 5 minutes is categorized as a minor stop. The time categories that exceeded their targets, as shown in Figure 6, are causes for the low OPI-Nona realizations, since during this time available for production, production is not possible. The high downtime can be elicited by numerous causes and Heineken already started several initiatives to investigate different aspects of the problem. The research of this thesis will focus on the maintenance aspects, which will influence the BCS target categories ‘breakdowns’ and ‘minor stops’. Indirectly, it can also influence the third category ‘planned downtime’.
1.4.
CHAPTER SUMMARY
This first chapter introduced the problem statement of Heineken: production line 7 did not reach its performance target from April till August, 2012. The high unplanned downtime of the line has a great share in this. Heineken already started initiatives on several aspects to reduce its high unplanned downtime. This research will focus on the maintenance aspect and thereby especially on the breakdown time.
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2. ANALYSIS OF THE PROBLEM STATEMENT Chapter 1 provided an introduction of the research location and the problem statement of Heineken. In this chapter, the problem will be analysed in more detail. Firstly, the specific research area will be determined, which will be the largest disturbed technical system of production line 7. In the second section, the current maintenance concept of that technical system is provided. Section 2.3 provides an overview of the related maintenance costs.
2.1.
DETERMINING RESEARCH AREA
30000 25000 20000 15000 10000 5000 0
Minor stop Breakdown
Depalletiser 71 Depalletiser 72 Crown cap 71 Filler 71 Crown cap 72 Filler 72 Pasteur Labeler 71 Labeler 72 Packer 71 Packer 72 Box closer 71 Box closer 72 Interior inserter 71 Interior inserter 72 Box setup 71 6-Pack setup 711 6-Pack setup 712 6-Pack inserter 71 Box setup 72 6-Pack setup 721 6-Pack setup 722 6-Pack inserter 72 Palletiser 71 Palletiser 72
Time [Minutes]
In this section we further analyse the low OPI-Nona performance of production line 7, caused by a high amount of available production time while nothing is produced. The performance of the line is examined on technical system-level, to determine the largest disturber of the production process. That techincal system will be the research area.
FIGURE 7: UNPLANNED DOWNTIME TECHNICAL SYSTEMS LINE 7, JAN-AUG 2012
Figure 7 shows the unplanned downtime of each technical system of line 7 in 2012 (till August). It can be seen that especially the packers suffer from high downtime, compared to the other technical systems of the line. The total unplanned downtime of the two packers was about 50.000 minutes (on average 25.000 minutes per packer) of the total 300.000 minutes the production line was manned (operators working at the line) in 2012 untill August. The average unplanned downtime of one packer per week is more than 8% of the time it is manned and it should be producing. On average, the manned time of a packer is 480 minutes per shift, 15 shifts a week: 7200 minutes. An increase of production of the fillers of 72 minutes per week will increase OPI-Nona with 1%. However, unplanned downtime of a packer does not directly cause unplanned downtime of the fillers. As is shown in Figure 4, there are 2 technical systems (the pasteurizer and the labellers) between the fillers and the packers. Therefore, the correlation between the breakdown time of the packers and the time the fillers are not able to produce since their output is jammed is calculated; resulting in a correlation in 2012 of 45%. Hence, an increase of 1% OPINona per week requires a decrease of unplanned downtime of the packers of 160 minutes (72/0,45). Figure 8 provides an overview of the breakdown time of the packers of line 7 (stops longer than 5 minutes), from January 2010 until August 2012. Data showed that April 2010, January 2011 and October 2011 are months with high planned downtime, compared to the other months. That probably explains the low breakdown time in those months. It is interesting to see that the breakdown time has increased over the last two years; in 2010 the breakdown time was on average less than in 2011 and 2012. It particularly increased after 2010, with an exceptional peak in the summer months (June and August), which is of huge influence on the OPI-Nona realization. 4
Breakdown
2010 February March April May June July August September October November December 2011 February March April May June July August September October November December 2012 February March April May June July August
Time [Minutes]
5000 4000 3000 2000 1000 0
FIGURE 8: DEVELOPMENT BREAKDOWN TIME PACKERS LINE 7
Because of the current high breakdown time of the packers and the increase of breakdown time over the years, it is determined to define the packers as research area.
2.2.
CURRENT MAINTENANCE CONCEPT PACKERS
The maintenance concept of a technical system is the collection of rules that describe maintenance: what maintenance activity is required, when maintenance should be performed, how each task should be performed and who should execute the maintenance task (Gits, 1992). A maintenance task describes the maintenance activities for one component. Each maintenance task exists of a maintenance policy, which is a rule that describes when a maintenance activity should be executed and a maintenance activity type, which prescribes what type of activity is executed to maintain a component (e.g. replacement or repair). The current maintenance concept of the packers of line 7 constists of the following:
Several components have maintenance tasks that prescribe an inspection of the condition of that component. Six inspection cards, documented in the software program SAP, describe which component should be inspected on which interval. In case the condition of the component is not sufficient anymore, it is directly maintained. There are no rejection criteria specified that prescribe when the condition of component is sufficient or not. That decision is made by the maintenance expert based on his experience and knowledge. Additionally, the operators have a CILT (Cleaning-Inspecting-Lubricating-Tightening)-list, which prescribes what CILT related activities should be executed at what moment. They are not actual maintenance activities, although they contribute to the condition of the system, i.e. sufficient cleaning of the chains and sprockets and lubricating the bearings increase their life time. The remaining components are used as long as they work and are replaced at the moment they fail.
Line 7 has several moments when operators are available whilst according to schedule the line is not producing, called planned downtime. During planned downtime, maintenance activities can be executed. The following list gives an overview of the planned downtime moments of line 7:
Stop day: Every 3 weeks, during the early shift on Thursday, the line is down and empty for maintenance. During this shift, inspections according to the maintenance concept are executed, maintenance orders are accomplished and operators execute cleaning tasks. From January until June 2013, line 7 will produce in 5-shifts schedule, which means production will be 24 hours a day, 7 days a week. Then, the stopday will be every 2 weeks, based on legal regulations, which require cleaning of the filler every 15 days which takes at least 4 hours.
Revision: The revision is 2 weeks of planned downtime, every 2 years. Three months before the revision moment, the maintenance department inspects the whole line, called the R-3, to determine
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which maintenance activities should be executed during the revision. This provides time to order all required components and equipment. During a revision, all maintenance tasks determined with R-3 are accomplished.
2.3.
COST OF MAINTENANCE
The costs of maintenance regarding the maintenance budget of a production line include the costs of spare components, costs of labour of the maintenance experts and costs of third parties that execute maintenance activities for the technical system. The maintenance costs on technical system level are registered via SAP. Figure 9 shows the maintenance cost of the packers of line 7 (black line) per year. € 120.000,00 Total Modification Preventive maintenance order Corrective breakdown Corrective repair Repair after inspection
€ 100.000,00 € 80.000,00 € 60.000,00 € 40.000,00 € 20.000,00 € 0,00 2006
2007
2008
2009
2010
2011
2012
FIGURE 9: COSTS OF MAINTENANCE OF THE PACKERS LINE 7, 2006 - 2012
Costs are divided over five categories:
Modifications (red line), which are permanent changes of the technical system. Preventive maintenance orders (green line), which are orders that are executed to prevent a breakdown. Those activities are not urgent and can be planned in the coming weeks. Corrective breakdowns (purple line), which are maintenance costs made to solve a breakdown of the machine, while production was held up through that breakdown. Corrective repairs (blue line), which are costs made during a repair, while production is not held up. Repair after inspection (orange), which are costs of maintenance activities executed after an inspection of a component.
When evaluating those cost categories, it is remarkable that the maintenance costs of repairs after an inspection are low, while the current maintenance concept exists only of inspections. While the corrective breakdown and corrective repair costs are a large part of the total costs. It seems that most inspections according the maintenance concept do not result in maintenance activities. Possibly, the inspections are held too often or the wrong components or failure modes are inspected.
2.4.
CHAPTER SUMMARY
From the analysis of the problem statement of Heineken we conclude that the packers have the largest negative impact on the low OPI-Nona performance of line 7, mainly caused by their high unplanned downtime (breakdown time and minor stops). Additionally, this chapter provided information about the current maintenance of the packers of line 7. It explained the current maintenance concept and the planned moments of downtime, used for cleaning and maintenance tasks. Based on the information of this chapter and Chapter 1, the research design for this project will be given in the next chapter.
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3. RESEARCH DESIGN This chapter provides the research design of this project, based on the information discussed in the first two chapters. Firstly, the research goal and question are formulated. The restrictions in this project are given in section 3.3. Then, the research deliverables are listed and lastly, the outline of the report is presented.
3.1.
RESEARCH GOAL
The goal of this master project is to increase the OPI-Nona of production line 7 up to its target of 67,08% by reducing its breakdown time of the packers, through the development of a new maintenance concept, with the lowest possible costs within the maintenance budget of the packers. Additionally, this research aims to provide better insight in the required planned downtime for maintenance activities and the expected maintenance costs.
3.2.
RESEARCH QUESTIONS
With this research goal, the main research question can be formulated: Can Heineken Zoeterwoude increase the OPI-Nona of production line 7, through reduction of the breakdown time of the packers, by improving the maintenance concept of that technical system, taking a budget restriction into account? In order to be able to develop a new maintenance concept that will fulfill the objective of having less unplanned downtime and thereby improving the OPI-Nona performance of the production line, first the general method and tools of Heineken will be investigated. Firstly, it will be investigated what trigger at Heineken is used to evaluate (and improve) current maintenance concep of a technical system. Additionally, feedback loops for maintenance concepts mentioned in literature will be reviewed. With this information, the following question will be answered: 1.
Is the current control- and feedback loop of Heineken that updates the maintenance concepts working properly or could it be improved?
Then, it will be examined according which method currently a maintenance concept is reviewed and improved at Heineken. This method will be compared to several maintenance concept development frameworks from literature. With this review, it will be decided which maintenance concept development framework will be used to execute the research goal: develop a new maintenance concept for the packers of line 7. This will answer the following question: 2.
Via which framework is a maintenance concept currently developed and could it be improved?
In a maintenance concept, maintenance policies prescribe when to execute a maintenance activity for a specific component. The maintenance policies used by Heineken will be compared to maintenance policies mentioned in literature. The question below will be answered: 3.
Which maintenance policies are currently applied by Heineken and are there additional interesting policies that should be taken into account?
Regarding the maintenance policies, Heineken developed two tools to determine which maintenance policy to apply on which component. Those tools will be reviewed and confronted with maintenance policy decision tools investigated in literature. That will answer the question: 4.
What maintenance policy decision tools are currently used by Heineken and should those be redesigned, based on the literature review? 7
3.3.
RESEARCH RESTRICTIONS
In executing this research and developing a new maintenance concept for the packers of line 7, several restrictions of Heineken should be taken into account:
Heineken aims to solve their problems according their own developed standards, frameworks and tools. It is preferred to use those as much as possible during this research. Those methods are explained and evaluated in this research. Another restriction is to accept the current standards regarding outsourcing. For line 7, no equipment maintenance is outsourced to third parties and this will not be changed. Additionally, the moments planned to execute maintenance are determined by Heineken and those should be used in the new maintenance concept. It will be possible to add extra spare components to stock if that is required according the new maintenance concept. However, the spare components currently in stock cannot be removed from stock since those are also used for other production lines. Additionally, the costs of holding spares in stock are not taken into account, since those are unknown by Heineken and currently not used.
3.4.
RESEARCH DELIVERABLES
Based on the research goal and the main research question, the following deliverables of this research are determined:
A redesign of Heinekens framework to improve maintenance concepts, based on a literature review. A redesign of the maintenance policies used by Heineken, based on a literature review. A redesign of the maintenance policy decision tools of Heineken, based on a literature review. A maintenance concept fo the packers of line 7, as a case study of the redesigned framework.
For specific information and equipment knowledge, a project team of Heineken personnel is initiated that will execute the case study on the packers of line 7, consisting of:
An operator who mainly works at the packers of line 7. A team technician predominantly operating within the dry part of line 7. A maintenance expert of the maintenance department with the packer as his specialism.
With this team, the redesigned framework will be executed for the packers of line 7. The newly developed maintenance concept should be implemented in the following documents. These are deliverables of the project team:
Maintenance cards with SMART (Specific, Measurable, Attainable, Relevant, Timely) maintenance tasks in SAP. BOM (Bill of Material) of the packers. Plan of action for the revision. New Cleaning, Inspecting, Lubricating and Tightening (CILT)-lists.
3.5.
REPORT OUTLINE
The outline of this report is shown in Figure 10. The first chapter provided the initial problem statement of Heineken, which was further analyzed in Chapter 2. With that knowledge, a research design is developed in this third chapter. Then, firstly the theoretical aspects of this research are discussed (Chapter 4-10); to latter apply them in a practical way on the packers (Chapter 11-13). 8
Introduction initial problem statement (Ch1)
Analysis of the problem statement (Ch 2)
Used as input Chapter Appendix
Research design (Ch 3) Theoretical Literature review frameworks (APP D)
Dynamic maintenance concept (Ch 4) Maintenance concept development framework (Ch 5)
Explanation several steps redesigned framework: Review criticality Step ‘Determine Maintenance Significant matrix (APP F) Components’ (Ch 6) Literature review policies (APP G)
Step ‘Determine relevant maintenance policies’ (Ch 7)
Literature review tools (APP H)
Step ‘Determine possible maintenance policies’ (Ch 8) Step ‘Determine optimal policy parameter values’ (Ch 9) Step ‘Determine maintenance concept’ (Ch 10)
Practical application Execution phase 1 (Ch 11)
Execution phase 2 (Ch 12)
Execution phase 3 (Ch 13)
Conclusions & recommendations (Ch 14)
FIGURE 10: REPORT OUTLINE
Chapter 4 will answer the first research question, since it develops the trigger for the improvement of a maintenance concept. APPENDIX D provides the literature review about maintenance concept development frameworks. This will be used as reference in Chapter 4. The Maintenance Optimization method of Heineken and the redesign of that method, based on literature, are provided in Chapter 5. This will answer the second research question. The literature review from APPENDIX D is also used as reference for this chapter. The chapters 6 till 10 will each explain a step from the redesigned framework of Chapter 5. Firstly, Chapter 6 will clarify the step ‘Determine Maintenance Significant Components’; a step of the redesigned framework that was not included in the framework of Heineken. APPENDIX F provides background information of this step. Chapter 7 will explain how to execute the step ‘Determine relevant maintenance policies’. This chapter is based on the literature review of APPENDIX G and will provide the answer on research question 3. Then, in Chapter 8, the step ‘Determine possible maintenance policies per MSC’ is explained. A literature review of maintenance policy decision tools is used in the confrontation with the tools of Heineken and is provided in APPENDIX H. Next, Chapter 9 will inform about the execution of the step ‘Determine optimal policy parameter values’. The last chapter of the theoretical part of this thesis, Chapter 10, describes the content of the step ‘Determine maintenance concept’. The chapters 8, 9 and 10 form an answer to the last research question.
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Then, in the practical part of this research, the redesigned framework and the included steps are executed. Chapter 11 will describe the application of the first phase of the redesigned framework; the preparation phase. Then, Chapter 12 explains the execution of the steps of the development, which is the second phase of the redesigned framework. The third and last phase of the redesigned framework, the evaluation phase, is discussed in Chapter 13. Lastly, Chapter 14 will provide the conclusion of this research and recommendations regarding this research for Heineken.
3.6.
CHAPTER SUMMARY
Chapter 3 described the research design to investigate the problem statement of Heineken. This research will develop a new maintenance concept for the packers of line 7, with the objective to improve the OPI-Nona performance of the production line by having less unplanned downtime through breakdowns. The maintenance concept should be executable within a certain maintenance budget. Before developing a new maintenance concept for the packers of line 7, the Maintenance Optimization and its tools used by Heineken will be reviewed and improved if possible.
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4. ESTABLISHMENT OF DYNAMIC MAINTENANCE CONCEPTS Chapter 1 introduced the topic of this research; the maintenance concept of the packers should be improved. In this maintenance concept, only one maintenance task is changed once during the last 6 years; it is a so-called ‘static’ maintenance concept. This chapter will firstly investigates what currently triggers the decision to review a current maintenance concept of a technical system. Then, an overview of feedback loops from literature is provided and compared with the trigger of Heineken. Lastly, a new trigger system will be presented to keep updating and continuously improving a maintenance concept, with information that is gathered during the application of the maintenance concept.
4.1.
CURRENT TRIGGER FOR MAINTENANCE CONCEPT IMPROVEMENT AT HEINEKEN
Figure 11 represents the current situation of an maintenance concept. An existing or new technical system is the input. Then, a maintenance concept is developed and its output is the new maintenance concept for that technical system. That maintenance concept is implemented and used for years, called a static maintenance concept. Heineken states to use the Plan, Do, Check, Act (PDCA) cycle, the continuous improvement method of Shewhart (1939). This contains to check an implemented maintenance concept and act when it is not functioning as required. However, the current maintenance concept of the packers of line 7 is developed in 2000 and since then only 1 adjustment is made, while the problem introduction (section 1.3) stated that the maintenance concept does not prevent the breakdowns as required. It seems that the PDCA-cycle did not work for the maintenance concept packers of line 7, since the concept is FIGURE not improved after disappointing results.
11: CURRENT CONCEPT IMPROVEMENT
4.2.
PROCESS
MAINTENANCE
TRIGGER FOR MAINTENANCE CONCEPT IMPROVEMENT FROM LITERATURE
Over time, you learn more about the behavior of a technical system and its components. Reviewing the performance of a maintenance concept and its impact on the technical system will provide more data of e.g. the lifetime of components and required planned downtime. A maintenance concept that is changed over time is called a dynamic maintenance concept. Literature broadly mentions the importance of continuously improving the maintenance concept of a technical system. However, the trigger when to review and improve a maintenance concept differs. A broadly used trigger for maintenance concept improvement is to monitor the performance of the current maintenance concept and review it when results are below required. Vanneste & Wassenhove (1995) developed a framework for maintenance concept improvement, with a last step called ‘monitor actions and process data’. This includes adapting plans or procedures in case of undesired deviations while executing the maintenance concept. In the maintenance concept development framework of Wayenbergh & Pintelon (2002), the last step is ‘performance measurement and continuous improvement’. They state that the performance of the maintenance concept should be measured, to identify the areas of improvement and enhance the maintenance concept.
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4.3.
NEW TRIGGER FOR MAINTENANCE CONCEPT IMPROVEMENT FOR HEINEKEN
The PDCA-cycle in general is applied by Heineken, although it seems not to result in the desired improvement of maintenance concepts. Currently, the maintenance concepts of Heineken are static, while literature provides the benefits of a dynamic maintenance concept. Therefore, it is decided to make clear guidelines that prescribe when to review and improve the maintenance concept of a technical system (Figure 12). With the maintenance experts and the project team, it is decided to recommend to review and improve a maintenance concept in case the breakdown time, as defined and measured by the BCS (section 1.3), is exceeded 3 months successively. This can easily be checked with the standard monthly performance reports. Exceeding the target in one month can occur, due to a large unplanned breakdown that is taken into account in determining the maintenance concept. However, if the breakdown time target is exceeded for 3 successive months, the maintenance experts expect that it is not an incidential breakdown. FIGURE 12: NEW TRIGGER START MAINTENANCE CONCEPT Additionally, if the breakdowntime target is already IMPROVEMENT exceeded for 3 months, it is getting difficult to reach the determined production target (OPI-Nona). Therefore, it is recommended by the project team to review the maintenance concept after 3 months of exceeded breakdown time targets. Additionally, it is recommended to review the maintenance concepts every 2 years, after revision of the line. Then, the maintenance experts have an indication of the condition of all components of a technical system and can determine if the current maintenance concept is sufficient for each one.
4.4.
CHAPTER SUMMARY
Section 4.1 explained that Heineken currently do not use their PDCA-cycle method to continuously improve the maintenance concept of a technical system: in the last 6 years only one adjustment is made to the maintenance concept of the packers, while performance is below target. In section 4.2, examples to trigger the improvement of a maintenance concept from literature are presented. With this information, section 4.3 provided a new trigger system for Heineken, to keep their maintenance concepts improving with newly gathered information and establish dynamic maintenance concepts for Heineken. It is recommended to review a maintenance concept every 2 year after the revision of a technical system and also review it in case of disappointing results.
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5. FRAMEWORK FOR THE DEVELOPMENT OF A MAINTENANCE CONCEPT Chapter 4 described how Heineken can establish a dynamic maintenance concept for their technical systems. Now, the framework of how to review and improve a maintenance concept is provided; the content of the ‘black box’ in Figure 12. Firstly, the general phases of a maintenance concept development framework are determined. Then, the Maintenance Optimization (MO) method of Heineken is given and presented in a framework. Section 5.3 will provide an overview of several maintenance concept development frameworks from literature, based on the literature review provided in APPENDIX D. In section 5.4, the shortcoming of Heinekens framework are discussed in a confrontation with the literature review and based on experience in the company. Lastly, a redesigned framework which will be used in this research is presented and its application is explained.
5.1.
GENERAL PHASES IN THE MAINTENANCE CONCEPT DEVELOPMENT FRAMEWORK
To be able to compare the framework of Heineken with literature and to redesign it, a general classification of the phases of a maintenance concept development framework is developed. Based on several frameworks from literature (APPENDIX D), the three phases as shown in Figure 13 are identified. The first phase is the preparation phase, in which the required input for the development of a maintenance concept is gathered. In the second phase, a new maintenance concept is developed. The third and last phase checks the if the maintenance concept as developed in phase 2 fulfills the objectives and restrictions and include steps that implement it.
FIGURE 13: PHASES OF THE MAINTENANCE CONCEPT DEVELOPMENT FRAMEWORK
The steps of all frameworks, from literature as well as from Heineken, will be classified according the general phases as shown in Figure 13, in order to make them comparable.
5.2.
EXPLANATION ´MAINTENANCE OPTIMIZATION´ FRAMEWORK HEINEKEN
Originally, Heineken used the FMECA (Failure Mode, Effect, and Criticality Analysis) method, which is according to Thomas, Barton & Byard (2008): ‘an advanced planning technique aimed at systematically assessing all potential failures of a machine and the potential impact (criticality) of the failure on a human and/or the system’. An FMECA for a technical system is enormous time-consuming and since most of Heinekens systems are unique (only on one specific line), it was not worth it to spend that much time for the improvement of a single one maintenance concept. Therefore, Heineken developed their own method to improve an existing maintenance concept of a technical system by: (1) evaluating the current maintenance concept and (2) improve it to prevent occurred failures from occurring again in the future, while taking the current maintenance concept as starting point. It is called the Maintenance Optimization (MO) method. Heineken did not have a clear framework or explanation of the MO with the steps that should be executed. Therefore, the MO framework as shown in Figure 14 is constructed during this research by interviewing the maintenance experts and maintenance coordinators of Heineken. The 3 general phases identified in section 5.1 are used as guideline: Preparation, Development and Evaluation. In the first phase, available information is gathered as input for the next phase. Firstly, information about technical system, like drawings and a decomposition, are gathered. Secondly, the following maintenance information is required to gather: its lubrication plan, CILT-lists of the operators, the current maintenance concept from SAP, the revision plan, the revision evaluation last time, the bill of material and maintenance 13
contracts of third parties. In the third step, information about breakdowns is gathered; breakdown data of the last 12 months from the information system of Heineken (MES Verpakken), breakdown notifications from SAP of the last 12 months and Break Down Analyses (BDA) (analyses of breakdowns to find the failure mode and implement a countermeasure to prevent the breakdown from occurring again) of the last year. Phase 1 Preparation maintenance concept development
Phase 2 Development maintenance concept
Phase 3 Evaluation developed maintenance concept
Gather information technical system
Colour breakdowns in ISO-metric
Evaluate costs of determined tasks (â&#x201A;Ź PM < â&#x201A;Ź breakdown)
Gather current maintenance concept
Determine policy and tasks to prevent those breakdowns
Evaluate required time and spare parts for tasks
Gather data breakdowns of the last year
Colour maintenance activities in ISO-metric
Ask permission for adjustments
Evaluate current maintenance tasks and policies
Adjust documents of the maintenance concept
Phases framework Check implementation in all documents
Steps MO framework
FIGURE 14: MAINTENANCE OPTIMIZATION FRAMEWORK (HEINEKEN)
The second phase, the development of the maintenance concept, starts by colouring the components that broke down during the last 12 months in the isometric drawing. Then, it is determined for each breakdown if it could be prevented with a maintenance activity. Based on a decision tree is decided which maintenance policy should be used for that component. This decision tool is explained in the next chapter. Hereafter, the current maintenance activities (based on the gathered information) are coloured in the iso-metric drawing, as a starting point of the evaluation of all current maintenance activities. Are maintenance tasks required or unnecessary? Is the frequency of maintenance tasks optimized? Do the maintenance tasks perform as they are expected to perform? At the end of this phase, all current maintenance tasks are evaluated and improved when necessary and new tasks are developed. In the last phase, the developed maintenance concept will be evaluated. Firstly, the costs of the maintenance tasks are examined. Heineken defined the rule that a task should only be implemented if the preventive maintenance costs are lower than the (expected) breakdown costs. Then, for each maintenance task is the required time of a maintenance expert indicated and is checked if the required spares are in stock. This adjustment proposal should be approved by the management team of the rayon. Then, the documents related to the maintenance concept are adjusted. Lastly, it is checked if the adjusted maintenance concept is implemented in all documents.
5.3.
CONFRONTATION MO FRAMEWORK WITH FRAMEWORKS FROM LITERATURE
This section will firstly show an overview of several maintenance concept development frameworks and give a short summary of the literature review (APPENDIX D). Then, the MO framework of Heineken (shown in Figure 14) is confronted with literature, in a subsection per phase.
5.3.1. OVERVIEW LITERATURE MAINTENANCE CONCEPT DEVELOPMENT FRAMEWORKS The maintenance concept developement frameworks reviewed in this research are from Gits (1992), Vanneste & Van Wassenhove (1995) and Wayenbergh & Pintelon (2002). A literature review of those frameworks is given in APPENDIX D including an arrangement of the steps of each framework in general phases as shown in section 5.1. Table 1 shows the general phases, complemented with the steps of the three frameworks in the corresponding phase.
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The overview of the frameworks from literature give broader insight in the differences between them. It can be seen that in the first phase, the frameworks do not differ a lot. All require to gather the available information of the technical system and to set objectives and restrictions for the new maintenance concept. Even though the framework of Gits does not explicitly mention to gather information, he starts in the second phase with steps that require this input. In the second phase, the frameworks differ a lot. The goal to develop a maintenance concept is shared by all frameworks; however the method to reach this goal differs. The framework of Gits has a lot of attention for the scheduling and planning of maintenance activities (step 4 â&#x20AC;&#x201C; 6). Vanneste & Van Wassenhove use a cost-benefit analysis of all possible maintenance tasks to decide which to include in the maintenance concept. While Wayenbergh & Pintelon developed a decision tree (which content will be further discussed in section 8.2 and APPENDIX H) that prescribes which maintenance policy should be executed for each component. Then, they focus on optimizing the developed maintenance concept. In the last phase, Gits evaluates the developed maintenance concept by checking if it fulfills some objectives and preferences. The other two frameworks do not explicitly mention this check; however, the developed maintenance concept is implemented (which is only possible when it fulfills its requirements). Additionally, Vanneste & Van Wassenhoven and Wayenbergh & Pintelon both implement the maintenance concept as developed and monitor the performance measurement of it, with further improvements of the maintenance concept if it does not perform as required. TABLE 1: OVERVIEW STEPS DIFFERENT MAINTENANCE CONCEPT DEVELOPMENT FRAMEWORKS, CATEGORIZED PER GENERAL PHASE
Phase 1: Preparation
Gits (1992)
Vanneste & Van Wassenhove (1995)
Wayenbergh & Pintelon (2002)
-
Step 1: Obtain a clear picture of the current factory performance Step 2: Analyse quality and downtime problems Step 1: Start-up and identification of objectives and resources Step 2: Identification of the Most Important Systems Step 3: Criticality analysis
Phase 2: Development Step 1: Qualifying maintenance initiations Step 2: Specifying maintenance operations Step 3: Limiting maintenance intervals Step 4: Clustering maintenance operations Step 5: Harmonizing maintenance intervals Step 6: Grouping maintenance operations Step 3: Analyze effectiveness of alternative solutions to (major) problems Step 4: Analyse efficiency of maintenance procedures Step 5: Plan actions Step 4: Maintenance policy decision step Step 5: Optimization of the preventive maintenance policy
Phase 3: Evaluation
Step 7: Evaluating maintenance rules for (a) appraising maintenance costs, (b) characterizing maintenance demand and (c) classifying preventive maintenance
Step 6: Implement actions and gather data Step 7: Monitor actions and process data Step 8: Adapt plans in case of undesired deviations Step 6: Performance measurement and continuous improvement
5.3.2. CONFRONTATION PHASE 1: PREPARATION In the first phase, the MO method of Heineken does not vary a lot from the frameworks from literature. They all require to gather the available information of the technical system and to set objectives and requirements for the new maintenance concept. Although, there are some differences. Firstly, Heineken reflects the breakdowns of only the last year, while frameworks from literature do not specify a time limit for data. Secondly, Gits (implicitly) and Vanneste & Van Wassenhove set objectives and requirements which the 15
maintenance concept should fulfill. Heineken has a motivation to review and improve a maintenance concept; as for the packers of line 7 is described in the initial problem statement in section 1.3. However, this motivation is not formulated in clear objectives or restrictions that should be fulfilled by the new maintenance concept. From experience it is know that Heineken may have similar technical systems on different production lines (as well in the same brewery as in others), the other systems can provide insights and more information. However, those are not taken into account in the current framework. Additionally, a note about the data gathering should be made. It is revealed that the data gathered by the technical systems is not always correct. Therefore, it is important to verify the data before using it in the development of the new maintenance concept.
5.3.3. CONFRONTATION PHASE 2: DEVELOPMENT The framework of Heineken is focussed on preventing the breakdowns of the last year and evaluating the current maintenance concept; the current maintenance concept is the starting point of the new maintenance concept. However, the frameworks investigated from literature do not take a current maintenance concept into account. Since it is not clear where the current maintenance concepts of Heineken are based on (they are developed by maintenance experts, without clear guidelines), using the current maintenance concept as basis could bias a new maintenance concept. Another aspect is the decision of the optimal parameters of a maintenance policy, not mentioned in the MO framework. This aspect is included in the step ‘Limiting maintenance intervals’ of Gits and also Wayenbergh & Pintelon specifically appoint that optimal policy parameters for each component should be determined. Additionally, in the MO framework no attention is paid at the planning and scheduling of the maintenance tasks, while Gits dedicates 3 steps of his framework on that subject. Lastly, all frameworks take different maintenance policies into account. For Heineken it would be interesting to determine which maintenance policies, outside their own ‘standard’ policies, could be relevant.
5.3.4. CONFRONTATION PHASE 3: EVALUATION In the last phase, the MO framework approves only tasks if the costs of preventive maintenance are less than the expected cost of an unexpected breakdown. However, it would be possible that those tasks are required to fulfil the determined objectives and restrictions. Wayenbergh & Pintelon and Vanneste & Van Wassenhoven have an additional step; continuous improvement of the maintenance concept. This is already discussed in Chapter 4 and therefore not taken into account in the redesign of the framework any more.
5.4.
REDESIGN FRAMEWORK
Based on the previous section, the MO framework of Heineken (Figure 14) is redesigned. Firstly, it is explained how the redesigned framework is constructed. In APPENDIX E is explained per step why it is added, removed or changed, categorized per phase. Section 5.4.2 provides a description of the content of the steps of the redesigned framework, as shown in Figure 15.
5.4.1. CONSTRUCTION OF THE REDESIGNED FRAMEWORK The 3 phases of the present frameworks (preparation, development and evaluation) will also be used in the redesigned framework (blue boxes). Figure 15 presents the adjustments of the MO method of Heineken (green steps in each phase), added with steps that are added based on literature or knowledge about Heineken (red steps). Steps that should be removed from the MO method are coloured in grey, yellow steps are steps from the original framework although moved to another moment in the framework. Of purple steps, the content is changed from the original step in the MO framework. APPENDIX E explains why steps are added, removed or changed.
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Phase 1 Preparation maintenance concept development
Phase 2 Development maintenance concept
Phase 3 Evaluation developed maintenance concept
Set objectives and restrictions
Color breakdowns in ISO-metric
Evaluate costs of determined tasks (€ PM < € breakdown)
Gather information technical system
Color maintenance activities in machines ISO-metric
Evaluate required time and spare parts for tasks
Gather current maintenance concept
Determine relevant maintenance policies for technical system
Evaluate objectives and restrictions
Gather data breakdowns of the last year
Determine / evaluate maintenance policy and tasks
Ask permission for adjustments
Gather data breakdowns longer than 1 year ago
Determine possible maintenance policies per MSC
Adjust documents of the maintenance concept
Verify the gathered data
Determine optimal policy parameter values
Gather data of breakdowns of similar technical systems
Check implementation in all documents
Determine maintenance concept
Gather data spare components
Determine required spare components
Determine Maintenance Significant Components (MSC)
Cluster / harmonize maintenance activities
Phases framework
Removed steps
Original MO-steps
Replaced steps
Added steps
Changed content
Group maintenance activities
FIGURE 15: ADJUSTMENTS OF THE MAINTENANCE OPTIMIZATION METHOD TO CONSTRUCT THE REDESIGNED FRAMEWORK
5.4.2. CONTENT OF THE REDESIGNED FRAMEWORK Figure 16 shows the redesigned framework, with all steps that should be executed. The content of the phases and steps are provided below. Phase 1 Preparation maintenance concept development
Phase 2 Development maintenance concept
Phase 3 Evaluation developed maintenance concept
Set objectives and restrictions
Color breakdowns in ISO-metric
Evaluate objectives and restrictions
Gather information technical system
Determine relevant maintenance policies for technical system
Ask permission for adjustments
Gather current maintenance concept
Determine possible maintenance policies per MSC
Adjust documents of the maintenance concept
Gather data breakdowns
Determine optimal policy parameter values
Check implementation in all documents
Verify the gathered data
Determine maintenance concept
Gather data of breakdowns of similar technical systems
Determine required spare components
Gather data spare components
Cluster / harmonize maintenance activities
Determine Maintenance Significant Components (MSC)
Group maintenance activities
Phases framework Steps redesigned framework
FIGURE 16: REDESIGNED FRAMEWORK
The goal of the first phase is to gather all information and data available of the technical system, required to develop a maintenance concept. Together with the project team it is determined which sources of data are useful to take into account.
Set objectives and restrictions. In this step, the goals for the new maintenance concept are determined, like the available budget and the maximal acceptable breakdown time. Additionally, restrictions for the new maintenance concept are formulated, like the planned downtime moments available for maintenance and the capacity of the maintenance experts. 17
Gather data breakdowns. Via MES Verpakken and SAP, available data of breakdowns should be gathered. This provides an overview of the critical components of the technical system and recurring breakdowns. Verification data. The gathered breakdown data of the previous step can be vague, questionable and sometimes unreliable. Therefore, it is important to check the reliability of the gathered data. Gather data breakdowns similar technical systems. Heineken has breweries all over the world and Heineken Zoeterwoude cooperates a lot with especially the breweries in Den Bosch and Wielre. Those breweries have similar production lines as Zoeterwoude with similar equipment. Additionally, Zoeterwoude has similar production lines in their own brewery. Comparing the breakdowns of similar technical system provide better insight in the critical components and lifetime of components. Gather data spare components. The consumption of spare components provides also insight in the life time of components. Additionally, it is important to know which spare components are already in stock in the brewery and which of them are also used on other technical systems. Determine Maintenance Significant Components. In this step it will be determined which components of the technical system should be taken into account in the maintenance concept and which not. This step will further be discussed in Chapter 6.
In the second phase, the maintenance concept will be developed, based on the gathered data of the first phase.
Determine relevant maintenance policies. In this step it will be determined which maintenance policies could be relevant to apply at the technical system. In Chapter 7, the content of this step and the explanation on how to execute it are provided. Determine possible maintenance policies per MSC. Not all maintenance policies relevant for a technical system are applicable at each Maintenance Significant Component (MSC). In this step it will be determined which maintenance policies are technically feasible for each MSC. Chapter 8 explains how to execute this step. Determine optimal policy parameter value. For each possible maintenance policy of each MSC it will be determined which policy parameter corresponds to the lowest costs, i.e. the preventive replacement interval or the inspection interval of a component. This step is further explained in Chapter 9. Determine maintenance concept. Then, per MSC a maintenance policy will be determined, which is the possible maintenance policy with the lowest costs during the remaining lifetime of the component. How to calculate those costs and which aspects to include, is explained in section 9.4.1. The objectives set in the first phase of this framework should be fulfilled and Chapter 10 explains how to determine the maintenance concept that fulfils the objectives and restrictions. Determine required spares. In this step, the spare components required to execute the maintenance concept as developed are determined. Cluster / harmonize maintenance activities. Some maintenance activities included in the maintenance require a start-up time, i.e. for an assembly that is not easily reachable. By clustering the maintenance activities for such an assembly, start-up time (and therefore labour costs of the maintenance experts) can be saved. Group activities. Lastly in this phase, a schedule of the maintenance activities over time will be developed, taking the planned downtime moments into account.
The last phase of the redesigned maintenance concept evaluates the developed maintenance concept and implements it.
Evaluate objectives and restrictions. In this step, it will be checked if the developed maintenance concept indeed fulfils the objectives and restrictions. This is a last control before implementing it. 18
ď&#x201A;ˇ ď&#x201A;ˇ
ď&#x201A;ˇ
Ask permission. The developed maintenance concept should be approved by the management of the production line, before it can be implemented. Adjust documents maintenance concept. The maintenance concept is scheduled in the SAP software at Heineken. Additionally, other documents support the maintenance concept, like inspection instructions, the bill of material with stock locations etc. All documents involved in the maintenance concept should be adjusted for the new maintenance concept. Check implementation. Lastly, it should be checked if all involved documents are adjusted and the new maintenance concept is implemented correctly.
5.5.
CHAPTER SUMMARY
This chapter evaluated the Maintenance Optimization method of Heineken (Figure 14) and based on literature and experience at Heineken, a redesign (Figure 16) has been developed. The redesigned framework will be applied in this research to develop a new maintenance concept for the packers of line 7. The following chapters will discuss several steps of the redesigned framework, as is already mentioned in section 5.4.2.
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6. CONTENT OF THE STEP ‘DETERMINE MSCS’ This chapter will explain the content of the step ‘Determine Maintenance Significant Components’, as announced in section 5.4.2. This is the last step of the first phase of the redesigned framework. The first section of this chapter explains the current method of Heineken (called ‘criticality matrix’) to determine which components of a technical system should be taken into account in the development of a maintenance concept. The second section presents the shortcomings of the criticality matrix of Heineken, based on a confrontation with literature. Then, a redesigned method that overcomes those shortcomings is provided. Lastly, it is explained how to execute the step ‘Determine MSCs’.
6.1.
EXPLANATION CRITICALITY MATRIX OF HEINEKEN
Heineken developed a criticality matrix to determine which components of a technical system are of relevance to take into account in the development of the maintenance concept and which are not. The criticality matrix distinguish the components based on their impact on the system, in important and less important components. Information about the exact method and calculations is provided in APPENDIX E. Figure 17 shows a table that summarizes the criticality of components, as defined by Heineken. Per component the probability of a breakdown is estimated (> 5 years, 1-5 years, 3-12 months, 1-3 months or <1 month). Then, the expected impact of a breakdown on five categories (Safety, Downtime, FIGURE 17: CRITICALITY MATRIX OF HEINEKEN Influence on the environment, Repair cost and Product quality) is determined. In Figure 17, the impact a each category in combination with the probability of the breakdowns corresponds to a coloured box. If at least one of the corresponding boxes of the impacts is red, that component is seen as critical part. Components that only correspond to green boxes are non-critical components. The criticality of a component is used as input for the tool that determines which maintenance policy to apply to the component (as will be explained in section 8.1).
6.2.
CONFRONTATION OF THE CRITICALITY MATRIX OF HEINEKEN WITH LITERATURE
Heineken uses a criticality analysis to determine if a component is critical or non-critical. The distinction between important and less important items is made in all maintenance concept development frameworks investigated in this research (as provided in APPENDIX D). However, the method how to exactly make this distinction differs per framework. The criticality analysis as used by Heineken is broadly used in literature. As explained in section 5.2, it is part of the FMECA method; a method to determine the impact of failure modes of components. Of the investigated frameworks, this FMECA is included in the RCM framework (Appendix D1.2) and the framework of Wayenbergh and Pintelon (Appendix D1.6). This type of tool could be useful to determine the importance of a component for Heineken. Although criticality matrixes are commonly used in literature, it does not seem useful to apply for Heineken. For each component identified as critical, a maintenance policy will be applied. However, the maintenance budget is limited, whereas in this way no attention is paid to the total costs of the developed maintenance concept. Therefore, section 6.3 will explain a redesigned method that will take the limited budget into account.
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6.3.
REDESIGN OF THE CRITICALITY MATRIX
Because of the shortcomings of the criticality matrix of Heineken as provided in section 6.2, it will not be used. In the redesigned framework, another distinction between components to include or not include in the maintenance concept is used. The term Maintenance Significant Component (MSC) is introduced, which is a component of a technical system that ever is maintained of or is included in the current maintenance concept. In the redesigned framework, all MSCs of a technical system are taken into account in the development of a new maintenance concept. All MSCs can cause unplanned downtime of the system and therefore, it is decided not to distinguish critical from non-critical MSCs before determining the maintenance policy per component. Applying the redesigned framework and taking all MSCs into account instead of the original criticality matrix of Heineken entails some risks. Firstly, the development of a new maintenance concept will presumably take more time, since more components are taken into account. Additionally, a component with high influence on safety, the environment or product quality is not mentioned separately any more. Although, also in the original criticality matrix of Heineken this influence is not further taken into account in determining which maintenance policy to apply (as will be explained in section 8.1).
6.4.
EXECUTION OF THE STEP ‘DETERMINE MSCS’
In the last step of the first phase, the MSCs will be determined. Together with the project team, the following sources at Heineken are identified to find all MSCs of a technical system:
All components that are mentioned in the current maintenance concept of the technical system. All spare components in stock of the technical system. All components that ever suffered from failure on the technical system (based on SAP). All components ever ordered at the supplier of the technical system. All components ever replaced or maintained during the revision of the technical system.
Components that are not taken into account are components that are never maintained or not expected to be maintained (and therefore not included in the stock of in the revision plan), e.g. the frame of the technical system and its covering. By including all MSCs in the maintenance concept, the estimated costs, required planned downtime and expected breakdown time is as predictable as possible.
6.5.
CHAPTER SUMMARY
In this chapter, the criticality matrix of Heineken is explained, which determines the relevant components for the maintenance concept. This criticality matrix has several shortcomings and those are discussed based on a confrontation with literature. Therefore, a redesigned method is developed: all components that are ever maintained will be taken into account in the development of the maintenance concept. These are called the Maintenance Significant Components (MSCs).
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7. CONTENT OF THE STEP ‘DETERMINE RELEVANT MAINTENANCE POLICIES ’ In this chapter, the step ‘Determine relevant maintenance policies’ will be discussed, which is the second step of the second phase. As mentioned in section 2.2, a maintenance policy is a rule describing when maintenance should be applied. Section 7.1 will explain which maintenance policies are currently used by Heineken. Then, an overview of maintenance policies mentioned in literature is provided. In section 7.3, the maintenance policies of Heineken are confronted with the maintenance policies from literature. Then, a redesign of the applicable maintenance policies is provided. Lastly, it is explained how the step ‘Determine relevant maintenance policies’ should be executed.
7.1.
MAINTENANCE POLICIES CURRENTLY USED AT HEINEKEN
Heineken states to use the maintenance strategy Reliability Centered Maintenance (RCM). The different maintenance policies used in the RCM strategy are:
Run to Failure (RtF) There are no preventive maintenance activities executed for that component. The component is used until it fails; in that case, it is maintained. Hence, the moment of maintenance depends on the unplanned breakdown of that component.
Condition-Based Maintenance (CBM) Components are inspected after a fixed period to check the condition of that part. Maintenance is only executed if the condition or performance of that part is below its specified criteria at the moment of inspection. The moment of maintenance depends on the condition of a component. However, in section 2.2 is already mentioned that there are no condition criteria specified for components. This judgement is made by the maintenance expert, based on his knowledge and experience.
Time-Based Maintenance (TBM) Components are maintained, after a fixed period (mainly in revision, every 2 years); the moment of maintenance is planned in advance.
Additionally, Heineken defines the maintenance policy ‘Predictive maintenance’ (shown in Figure 18):
Predictive maintenance Predictive maintenance is, like CBM, based on the condition of a component. Instead of only inspecting the component, the condition is measured and registered. With this registration, the deterioration of a component can be monitored. With this input is decided when to execute maintenance on that component. FIGURE 18: MAINTENANCE POLICIES USED BY HEINEKEN
7.2.
OVERVIEW MAINTENANCE POLICIES FROM LITERATURE
This section will provide information about maintenance policies mentioned in literature. Firstly, it is mentioned that maintenance can be classified in two categories, based on the moment of maintenance:
Maintenance after a failure, called Corrective Maintenance (CM). This type of maintenance is called ‘Run to Failure’ by Heineken and Gits (1992) and RCM use the term Failure-Based Maintenance. CM is defined as all maintenance activities as a result of a breakdown, to restore a component to its specified condition.
22
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Maintenance before a failure, called Preventive Maintenance (PM). This maintenance is applied to prevent a failure from occurring; maintenance is executed while the component is still functioning. In most literature, this class is split in two categories, based on the motive for preventive maintenance: based on time (Time Based Maintenance / TBM) or based on the condition of a component (Condition Based Maintenance / CBM).
Figure 19 gives an overview of maintenance policies from literature, grouped per maintenance policy category. For all maintenance policies based on time, a distinction is made, concerning the measurement of time: based on calendar time (real time, like weeks, months and years) or based on production time (amount of production time, as production hours of a technical system). Corrective Maintenance
Age-dependent policy Time Based Maintenance
Maintenance
Sequential preventive maintenance policy Block policy
Calendar time Production time Calendar time Production time Calendar time Production time
Continuous monitoring policy Preventive Maintenance
Condition Based Maintenace
Periodic inspection policy Sequential inspection policy
Calendar time Production time Calendar time Production time
Continuous monitoring policy Standard classification Maintenance policies
Predictive Maintenance
Calendar time
Periodic inspection policy
Production time
Sequential inspection policy
Production time
Calendar time
FIGURE 19: OVERVIEW MAINTENANCE POLICIES
Based on the composition shown in Figure 19, maintenance policies will be explained per category below. For further details, APPENDIX G provides a list with the references from literature per maintenance policy.
7.2.1. CORRECTIVE MAINTENANCE Corrective maintenance is maintenance after failure of a component, more specified policies do not exist. The maintenance activity type per policy application can differ; this will be discussed in section 7.2.6.
7.2.2. TIME BASED MAINTENANCE With Time Based Maintenance (TBM), components are maintained after a specific amount of time. Since the distinction between calendar en production time is explained above, only the content of the policy is explained. ď&#x201A;ˇ
Age-dependent policy: Preventive maintenance is applied when the component reaches a specified age and corrective maintained if it fails before that age. The advantage of this policy is that maintenance is based on the age of a component and thus dependent on the breakdown history of a component. The disadvantage of this policy is that this will difficult to schedule the maintenance activities on forehand, since the moment of planned maintenance will change after one unplanned maintenance activity.
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Sequential preventive maintenance policy: Preventive maintenance following unequal time intervals, based on the perspective that systems need more frequent maintenance if they get older. The advantage of this policy is that in an ageing technical system some components wear out faster. By determining the next maintenance moment after the execution of one, a good estimation of the life time can be made. Disadvantuous is that each person will make a different estimation of the new maintenance moment and that maintenance activities cannot be clustered in advance. Additionally, this is a specific way of working that is currently not standard at Heineken. Block policy: A periodic preventive maintenance policy, where a component is preventively maintained at fixed times, independent of breakdown and repair history of the component. The advantage of this policy that is know on forehand when planned maintenance will be executed and required spares can be ordered. The disadvantage is that the policy can prescribe to execute planned maintenance activity, even when an unplanned maintenance activity has just executed. For example, it is prescribed to replace a component, while it broke down the week before and was replaced at that moment. (This disadvantage is solved by the age-dependent policy).
7.2.3. CONDITION BASED MAINTENANCE With Condition Based Maintenance (CBM,) a component is inspected to check its condition. Maintenance is only executed if the condition or performance of that component is below a specified level at the moment of inspection. The periodic inspection policy and the sequential inspection policy can both be based on calendar time as well as production time.
Continuous monitoring policy: The component is continuously monitored. If the component reached a predefined state, it will be maintained at the first planned downtime moment. The advantage of this policy is that it is directly noticed when the condition of a component is not sufficient any more. This will make maximal use of the life time of a component. On the other hand, the disadvantage is that there should be established some trigger that will be noticed when the condition of the component is not sufficient any more. Periodic inspection policy: After a fixed amount of time, the component will be inspected. At that moment, it is determined if the components need maintenance or not. Advantageous is that the maintenance activities depend on the condition of a component, so it will make maximal use of the life time of a component. The disadvantage is that inspections should be executed with a certain interval that is small enough to inspect the deteriorated state and will costs time of the maintenance expert. Additionally, there are inspections executed even in the part of the life time of a component that it is just replaced and working properly. Sequential inspection policy: The component is periodically inspected, however not after a fixed period. At the moment of inspection, it is determined if the component needs maintenance or not. If not, it is decided when the next inspection should be executed; length of inspection intervals can differ. The advantage of this policy is that it solves the disadvantage of the periodic inspection policy. Inspections can be delayed until a deteriorated state is expected and from then on they can be executed with shorter intervals. The disadvantages of this policy are the same of the sequential preventive maintenance policy, as discussed in 7.2.2.
7.2.4. PREDICTIVE MAINTENANCE Predictive Maintenance is, like Condition Based Maintenance, based on the condition of a component. However, the condition is actually measured per component and is registered to monitor over time. With this information, the maintenance department can predict when a breakdown will occur and therefore when they have to undertake action. Since the only difference with Condition Based Maintenance is the registration of the measured condition and the same policies can be applied, those are not explained again. The advantages and disadvantages mentioned at each Condition Based Maintenance policy are similar if they are applied according Predictive Maintenance. 24
7.2.5. REMARKS ON THE CONSTRUCTED OVERVIEW OF MAINTENANCE POLICIES With information from literature, Figure 19 has been constructed and represents an overview of maintenance policies classified in maintenance policy categories. However, two remarks should be made about this overview. Firstly, this maintenance policy overview defines numerous maintenance policies as different policies. However, for particular circumstances or cases, some maintenance policies can be equal to another one in the tree. For example, if a component is used 24 hours a day, 7 days a week; calendar time is equal to production time and the policies with that difference are similar for this case (like age-dependent policy calendar time and age-dependent policy production time). This should be taken into account when using the overview. Secondly, Heineken sees Predictive Maintenance and Condition Based Maintenance as two different maintenance policy categories. CBM decides per inspection if maintenance is required, only follow up actions are registered. While with Predictive Maintenance, the condition is measured and progress of deterioration is recorded and is used to forecaste when maintenance will be required. For Heineken, this is a big difference of maintaining a component; however, in literature this distinction is less clear. Predictive Maintenance is mainly included in the Condition Based Maintenance category and not discussed separately. However, since those overviews are developed to be used by Heineken, this distinction is made.
7.2.6. MAINTENANCE ACTIVITY TYPE The previous sections described several maintenance policies according which a component can be maintained; it prescribes when maintenance should be applied. What type of maintenance activity should be executed is prescribed by the maintenance activity type. An overview of several maintenance activity types is provided in Figure 20.
Minimal repair: Restore the component to the condition it had before, to start production as soon as possible. This is also called ‘bad as old’ or imperfect repair. Perfect repair: Reparation of the component, to an ‘as good as new’ component. Replacement: The component is replaced by a new or repaired one. Repair time limit: Firstly, the component is repaired. If the repair takes longer than a predetermined time, the component is replaced by a new one. Failure limit: A component is replaced when the failure rate of a component reaches a specified level or when reliability of a component is below a specified level. Other failures are fixed through minimal repair. Repair cost limit: A trade-off is made between expected repair costs and replacement. If repair costs are below a specified level, the component is repaired; otherwise it will be replaced. Repair number counting: A component is replaced if its number of failures reaches a predetermined number, before it is fixed by minimal repair. Reference time: According to this decision model, a component is replaced if it fails after a predetermined time. Failures before that time are fixed through minimal repair.
This decision should be made for each component with its maintenance policy, to specifically determine what type of maintenance activity should FIGURE 20: MAINTENANCE ACTIVITY TYPES be executed.
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7.3.
CONFRONTATION MAINTENANCE POLICIES HEINEKEN WITH LITERATURE
Heineken claims to use the maintenance policies shown in Figure 18. This section will confront the maintenance activities and policies of Heineken with the literature review. The policies used by Heineken are coloured green in Figure 21. Corrective Maintenance
Age-dependent policy Time Based Maintenance
Maintenance
Sequential preventive maintenance policy Block policy
Calendar time Production time Calendar time Production time Calendar time Production time
Continuous monitoring policy Preventive Maintenance
Condition Based Maintenace
Calendar time
Periodic inspection policy
Production time
Sequential inspection policy
Production time
Calendar time
Continuous monitoring policy Standard classification Policies used by Heineken
Predictive Maintenance
Maintenance policies
Calendar time
Periodic inspection policy
Production time
Sequential inspection policy
Production time
Calendar time
FIGURE 21: MAINTENANCE POLICIES USED BY HEINEKEN
Presently, the maintenance concept of the packers exists of inspection tasks to check the condition of a component. The maintenance expert inspects those components and determines if the component is still sufficient or if it needs to be maintained. Half of the inspection cards need to be performed each 3 months; the other 3 cards have a frequency of 6 months. Hence, the maintenance activities can be categorized as Condition Based Maintenance with the periodic inspection policy, based on calendar time. Predictive maintenance is applied by Heineken for important and expensive components where deterioration is measurable. The condition is measured with fixed intervals and registered, according the predictive maintenance policy periodic inspection based on calendar time. In case of odd measurements, the interval can be increased as in the sequential inspection policy, also based on calendar time. Components not listed on any inspection card are maintained according Corrective Maintenance. Time Based Maintenance is applied at Heineken via the revisions that are held every two year. Based on experience, the maintenance department knows which components have to be replaced every revision. Hence, Heineken applies the TBM block policy, based on calendar time. The type of maintenance activity that is executed if a breakdown occurs or a component is maintained, it is not predetermined by a rule. There are no guidelines to determine which policy to use in what case or for what component; the operator or mechanic himself determines how he is going to solve the problem. The maintenance department indicates that they mainly use minimal repair and corrective replacement types (as shown in green in Figure 22), to get the system running again as fast as possible. In case of minimal repair, the system will be brought back to an â&#x20AC;&#x2DC;as good as newâ&#x20AC;&#x2122; state at the first planned downtime moment after the minimal repair. However, FIGURE 22: MAINTENANCE ACTIVITY some components cannot be minimal repaired and should be replaced in TYPES HEINEKEN (GREEN) 26
case of a failure. The maintenance activities types are not further taken into account in this research. Section 7.4.2 explains why that decision is made.
7.4.
REDESIGN NEW MAINTENANCE POLICIES AND MAINTENANCE ACTIVITY TYPES
Section 7.2 showed that there are more interesting maintenance policies then currently used by Heineken. Why the new maintenance policies could be relevant, will be explained below. In the second subsections is explained what benefit the other maintenance activity types could be for Heineken.
7.4.1. BENEFITS OF THE OVERVIEW OF MAINTENANCE POLICIES Firstly, it could be interesting for Heineken to base the maintenance tasks for components that deteriorate over production hours, on production time. Since the production time per week can differ, it is relevant to base the moment of maintenance on the production time instead of calendar time. For example, production line 7 produced last year according a 3-shift schedule (120 hours/week) and increases their production from January until June 2013 to a 5-shifts schedule (148 hours/week). Additionally, if there is a lack of orders, the line is shut down for several shifts or even days. The exact production hours of every week differ, for components with a relative short life time those hours difference can be of importance. The sequential policies for time-based maintenance and condition-based are also new for Heineken, but can be very beneficial. I.e. a component with an expected life time of 6 year does not require inspections in the first 4 years, but from then on it could be useful, with a decreasing interval over time. Lastly, the continuous monitoring maintenance policies are mentioned. If possible, it would be ideal to continuously monitor the performance of a component (direct or indirect) and when its condition reaches a predetermined state, it could directly be maintained. This option is currently not taken into account by Heineken.
7.4.2. BENEFITS OF THE OVERVIEW OF THE MAINTENANCE ACTIVITY TYPES Besides the maintenance policies, also a variety of maintenance activity types is shown. For each component, a maintenance activity type can be defined which describes how to act when maintenance should be executed. Benefits of adding the maintenance activity type is that Heineken can influence the maintenance activities to connect it with the overall goal of the maintenance concept. E.g. if the goal is to have minimal breakdown time, minimal repair and the time limit policy are of interest. However, if low maintenance cost should be aimed, the repair cost limit is more interesting, even it can lead to some higher downtime. Since the maintenance policy overview is already new for Heineken, the maintenance activity types will not be further taken into account in this research; it is assumed that all maintenance activities are replacements (as shown in red in Figure 23). Implementing the maintenance activity types in the FIGURE 23: MAINTENANCE ACTIVITY TYPES TAKEN INTO ACCOUNT IN maintenance concepts can be an improvement step for Heineken, with the THIS RESEARCH (RED) information given in this chapter and APPENDIX D. This will also be mentioned in the recommendations in section 14.2.
7.4.3. RISKS OF THE REDESIGNED METHOD The risk of applying the redesigned method as explained in this section is that new maintenance policies can be applied at a technical system. That are new ways of working with which Heineken is currently not familiar. Especially when the maintenance activity types are applied, the maintenance experts should be informed about the new working methods and standards. Another risk is that some maintenance policies and activity
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types require an investment before they can be executed. It is important to estimate those costs accurate and take them into account in the next steps.
7.5.
EXECUTION OF ‘DETERMINE RELEVANT MAINTENANCE POLICIES ’
In the first step of the second phase, it should be decided which maintenance policies from the overview of Figure 19 are of relevance for that particular technical system of Heineken. I.e. it should be checked if continuous monitoring is possible and if production hours are registered. The relevant maintenance policies are taken into account in the succeeding steps of the framework. If it is decided to also define a maintenance activity type per component, it should also be decided which activity types from the overview of Figure 20 are relevant for the technical system. Again, this is out of the scope of this research.
7.6.
CHAPTER SUMMARY
In this chapter, the step ‘Determine relevant maintenance policies’ is explained. Figure 19 showed an overview of several maintenance policies mentioned in literature. This overview will be used as guideline for the execution of this step, to determine which maintenance policies should be used in the succeeding steps of the redesigned framework. Additionally, the overview of the maintenance activity types (Figure 20) can be used to determine which maintenance activity types to take into account in the remainder of the framework. The maintenance activitiy types are out of the scope of this research and therefore not applied for the packer.
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8. CONTENT OF THE STEP ‘DETERMINE POSSIBLE MAINTENANCE POLICIES’ In the third step of the second phase of the redesigned framework, it is decided which maintenance policy (and maintenance activity type) is applicable for which Maintenance Significant Component (MSC). As mentioned in section 7.4.2, the maintenance activity types are not taken into account in this research, and therefore not mentioned in this chapter. To determine which maintenance policy to apply at a component, Heineken developed a maintenance policy decision tree that is explained in the first section. Secondly, shortcomings of the maintenance policy decision tree, based on literature and knowledge of Heineken are given. Section 8.3 presents a redesigned method of how to determine which maintenance policies to apply at each MSC. Lastly, it is explained how to execute the step ‘Determine possible maintenance policies’ of the framework.
8.1.
EXPLANATION OF THE MAINTENANCE POLICY DECISION TREE OF HEINEKEN
Heineken developed a maintenance policy decision tree which determines which maintenance policy should be applied at each component. Figure 24 represents the decision tree, prescribing which maintenance policy should be applied to which component. The outcome of the tree is one of the maintenance policies used by Heineken, as shown in Figure 18 in section 7.1. The outcome of the criticality matrix (section 6.1) is taken into account in the first question of this decision tree.
FIGURE 24: MAINTENANCE POLICY DECISION TREE OF HEINEKEN
If a component is categorized as not critical, it is asked if the failure is hidden. In case of a hidden failure, it is not directly detected that the component has failed. For example, if a bearing far away in the system is broken, the system can still produce and it is not detectable for an operator that the component has failed, while the broken bearing will influence the deterioration and performance of other components. Therefore, a component with a hidden failure should be regularly inspected to know if it failed, according general inspections of AM (Autonomous Maintenance, meaning inspections of operators). If the failure is not hidden, corrective maintenance is applied since it is directly clear that the component failed. For critical components, first it is determined whether the component has an increasing failure rate. However, Heineken does not provide a clear explanation of what an increasing failure rate is and how to determine it. An explanation of the failure rate from literature is provided in section 8.2.2. The next question asked for critical components is if deterioration is detectable, a question related to the Condition Based Maintenance policies and the Predictive Maintenance policies. Figure 25 shows the ‘Performance-Failure curve’ (P-F curve) that represents the condition of a component that degrades over time. At a specific point (green dot), it is detectable that the component starts to
29
deteriorate. From that moment on, the component can still function, until the point it actually fails (the red dot). For critical components of which deterioration is detectable, the possible policies are Condition Based Maintenance and periodic replacement (which is used as synonime for the block policy of Time Based Maintenance). The choice between CBM FIGURE 25: P-F CURVE HEINEKEN and the block policy is based on the costs corresponding to the execution of that maintenance policy. For critical components without an increasing failure rate and without detectable deterioration, the maintenance policy depends on their Time to Repair (TTR). Breakdown maintenance (corrective maintenance) is applied or a modification should be executed. Modification is not a real maintenance strategy and not mentioned in the overview in Figure 19, since it is a permanent adjustment of the system such that the failure mode of that component cannot occur anymore. More information about modifications is provided in section 8.2.1.
8.2.
CONFRONTATION MAINTENANCE POLICY DECISION TOOL WITH LITERATURE
A decisions tree is also broadly used in literature; however, content differs per tree. A literature review of several maintenance policy decision trees mentioned in literature is provided in APPENDIX H, which is used in this chapter.
8.2.1. MODIFICATION One of the results of the decision tree is the option ‘modification’. A modification is a permanent change of the technical system, since sometimes it can be better to modify a specific component. Although it is a design improvement of the machine and not an actual maintenance activity, according to Tsang (2002) it is one of the basic approaches to maintenance. As long as the goal of a modification is to: ‘improve reliability, enhance maintainability, minimize maintenance resource requirements and eliminate the need for routine servicing’. An example of a modification is to construct wheels at the side of the point of bottle separation blocks, to prevent bottles from falling down. However, a modification should only be applied if the optimal maintenance policy is already executed and does not perform as preferred. Currently, Heineken may possibly not apply the optimal maintenance policy per component, the first step is to improve that. If an modification would be applied, it is important to note that the modified component should be put in the maintenance decision tree and a maintenance policy should be chosen for the modified component.
8.2.2. FAILURE RATE As mentioned in section 8.1, Heineken does not provide an explanation of an increasing failure rate. Lewis (1996) defined the failure rate (also called hazard rate) as the change in probability that a component will fail in the next time interval. The failure rate can be classified in three categories, as listed below and shown in Figure 26 in the broadly-used bath-tub curve.
Decreasing Failure Rate (DFR): the probability that a component will fail in the next moment is lower than in the current moment.
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FIGURE 26: BATH-TUB CURVE CONSIDERING DEPENDENT FAILURE RATES (LEWIS, 1996)
TIME-
Constant Failure Rate (CFR): the probability that a component will fail in the next moment is equal to the probability of failure in the current moment. The probability of failure is constantly divided over time; failure is randomly distributed. Increasing Failure Rate (IFR): the probability that a component will fail in the next moment is higher than in the current moment; the older the product, the higher probability it will fail in the next moment (also called ageing).
For assigning maintenance policies to a component, it is of importance to know what type of failure rate a component has. Preventive maintenance is only useful for components with an increasing failure rate, since the probability of failure is getting higher in time. A failure rate can be calculated with the failure rate function or hazard function (h(x)), in expected number of failures per time unit. The hazard function h(x) depends on the failure distribution, as follows (Tan, 2011): ( )
( ) ( )
(8.1)
Input for this formula is based on the Time to Failure distribution, explained in the next subsection.
8.2.3. TIME TO FAILURE DISTRIBUTION The Time to Failure (TTF) of a component is the time between two successive failures of that component; the time between the moment of the use of a component until it fails and is going to be replaced. The TTF differs per component and per failure and is a variable according a particular probability function. This probability density function (pdf), notated as f(t), provides the probability that a component fails at the a certain point in time; T. The left graph of Figure 27 represents the curve of a pdf function that has a certain probability of failing at a specific moment. The probability that the component fails at or before that T, is the sum of probabilities it is not failed on all moments before. That can be calculated according the cumulative distribution function (cdf), notated as F(T). The blue area in the left graph of Figure 27 shows the area of cdf, which is drawn in the right graph of Figure 27. The formula below shows the relation between cdf and pdf: ( )
(
)
(
)
∫
( )
(8.2)
Based on historical data, the time to failure distribution of a component can be determined. With this distribution the expected number of replacements during a time interval, the failure rate and the probability that a component fails before the preventive replacement can be calculated.
FIGURE 27: RELATION BETWEEN PDF AND CDF DISTRIBUTION
8.2.4. SHORTCOMINGS OF THE MAINTENANCE POLICY DECISION TREE OF HEINEKEN Shortcomings of the maintenance decision policy tree of Heineken (shown in Figure 24) are listed below:
Non-critical component with a hidden failure (not directly seen when failed) should be inspected by an operator, according the decision tree of Heineken. However, some components will require experts’ 31
opinion and cannot be inspected by an operator, because of the lack of knowledge of them. Additionally, the inspection may require downtime and may require substantial time. These issues are not taken into account, although they can have high impact on the performance of the system. According to Heinekens decision tree, for all critical components it is determined if deterioration is detectable. If deterioration is detectable, the policy CBM is advised. Even if it does not have an increasing failure rate. While, according literature, preventive maintenance is only interesting to apply at components with an increasing failure rate. Additionally, it seems odd to not have an increasing failure rate, but deterioration is detectable. Deterioration usually indicates an increasing failure rate. For critical components without an increasing failure rate and without detectable deterioration, the Time to Repair (TTR) determines if corrective maintenance is applied or a modification is preferred. However, this downtime is asked per component, while it should be focused on the total TTR of all components in the technical system. For example, it may be acceptable that one chain has a TTR of one hour; however, if there are 50 chains in the system, a total TTR of 50 hours is not acceptable any more. For components with an increasing failure rate with detectable deterioration, the question is asked if the costs of Condition Based Maintenance are lower than for Time Based Maintenance. At Heineken, the maintenance department is an internal service department for the rayons providing free services. Hours of personnel of the maintenance department are not charged to the rayons. Therefore, inspections of maintenance experts are ‘free’ and the CBM costs are not complete. If deterioration is detectable and CBM is less costly than TBM, CBM is applied. However, the delay time of the P-F curve as shown in Figure 25 is not taken into account. For example, a delay time of 1 day would require inspection with a very high frequency to be able to detect deterioration, that it is not lucrative.
8.3.
REDESIGN OF THE MAINTENANCE POLICY DECISION TREE
Based on the discussed shortcomings of Heinekens current maintenance policy decision tree and the literature review in APPENDIX H, the method on how to determine which maintenance policy to apply for which MSC is redesigned and split in 3 substeps, resented in Figure 28. The green box is the current step of Heineken and the 3 blue boxes are 3 steps as will be used in the redesigned framework. Firstly, for each MSC it will be determined which maintenance policies are technical possible to apply. A ‘maintenance policy possibilities tree’ will be used; a tree that determines which maintenance policies are technically feasible for a component. How to construct the tree will be explained in section 8.4. If maintenance activity types are also taken into account and in the previous step of the framework is determined which are relevant for the particular technical system, a ‘maintenance activity type possibilities tree’ should also be developed to determine FIGURE 28: REDESIGN STEP DETERMINE MAINTENANCE which activity types are applicable for each MSC. POLICY PER COMPONENT
Secondly, for each possible maintenance policy the parameter value with the lowest costs will be chosen. This is done in the fourth step of the second phase and is explained in Chapter 9. Then, the maintenance concept is determined (explained in Chapter 10). Per MSC the possible maintenance policies with the policy parameter resulting in the lowest cost are known. In step 5 of the second phase of the redesigned framework, for each MSC the maintenance policy with the lowest cost will be included in the initial maintenance concept. The different costs per MSC are compared and the policy with the lowest costs will be
32
included in the maintenance concept. Then, it is checked if the maintenance concept fulfils the set objectives. If not, an improvement method is provided in section 10.3. The risk of applying the three new steps instead of the step of the original framework of Heineken is that the maintenance concept will be based on calculations, not on the gut feeling of the maintenance experts. This requires an accurate estimation of the numbers, times and costs and take all relevant aspects (like waiting time and searching for the broken component) into account.
8.4.
EXECUTION OF ‘DETERMINE POSSIBLE MAINTENANCE POLICIES’
The third step of the second phase of the redesigned framework determines which maintenance policy should be applied for which MSC. Per MSC, the substeps as described in the following subsections should be taken.
8.4.1. SUBSTEP A: DEVELOP A MAINTENANCE POLICIES POSSIBILITIES TREE In the first substep, a maintenance policies possibilities tree should be developed, as a tool to determine which maintenance policy is applicable for which MSC. A general maintenance policy possibilities tree is shown in Figure 29. As is mentioned before, preventive maintenance is only applicable at components with an increasing failure rate. This question is asked to determine if preventive maintenance is feasible. Besides, Condition Based Maintenance and Predictive Maintenance are only applicable if deterioration is detectable. Thus with the second question is checked preventive maintenance policies besides Time Based FIGURE 29: GENERAL MAINTENANCE POLICY POSSIBILITIES TREE Maintenance are feasible. The exact content will differ per technical system, depending of the maintenance policies taken into account, as determined in the step ‘Determine relevant maintenance policies’ (explained in Chapter 7). Additionally, it can be further specified for exact maintenance policies, when it is known which of them are taken into account.
8.4.2. SUBSTEP B: ACCOMPLISH THE TREE FOR EACH MSC Then, each MSC should be put in the developed maintenance policy possibilities tree, to determine which maintenance policies are technical applicable at that specific component. The possible maintenance policies for each MSC are used in the next step: ‘Determine optimal policy parameter values’, that will be explained in the next chapter.
8.5.
CHAPTER SUMMARY
This chapter explained the maintenance policy decision tool as currently used by Heineken, called the maintenance policy decision tree. After a confrontation with literature, the second section provided shortcomings of the tool. With that knowledge, a redesign of the step is provided in the third section. The step of determining which maintenance policy should be applied at a component is split in 3 new steps. Firstly it will be identified which maintenance policies are technical applicable at the MSC. Secondly, the optimal parameter value of each possible policy will be determined (how to do that will be explained in Chapter 9) and lastly, the policy with the lowest costs will be included in the maintenance concept (explained in Chapter 10).
33
9. CONTENT OF THE STEP ‘DETERMINE OPTIMAL POLICY PARAMETER VALUES ’ The fourth step of the second phase of the redesigned framework determines the optimal policy parameter values of each possible maintenance policy of each MSC. A policy parameter is for example the age for the agedependent maintenance policy, the inspection interval for CBM and the block interval for the block policy. Firstly, this chapter describes the method currently used by Heineken. In section 9.2, shortcomings of that method are mentioned, based on literature. Then, a redesigned method is developed and in the last section, the execution of the step ‘Determine optimal policy parameter value’ is explained.
9.1.
CURRENT METHOD OF DETERMINING OPTIMAL PARAMETER VALUES HEINEKEN
This step is newly added to the redesigned framework. Heineken currently does not use a specified method of determining the optimal policy parameter value of a maintenance policy. The maintenance policy for a component is determined according the maintenance policy decision tree of Heineken (as shown in Figure 24 and explained in section 8.1) and then the team of maintenance expert decides which parameter should be applied, based on their experience.
9.2.
CONFRONTATION METHOD OF HEINEKEN WITH LITERATURE
The shortcoming of the current method of Heineken seems simple; there is no evidence that the chosen parameter value is optimal for the maintenance policy of that particular MSC. Additionally, it is not known what the chance is that it fails before the determined time interval and what the expected maintenance costs are related to the use of this policy parameter value. In literature, several aspects that influence the optimal parameter value are discussed. Those are presented in the following subsections.
9.2.1. NUMBER OF EXPECTED REPLACEMENTS The policy parameter values of the periodic replacements according the block policy and age dependent policy is the replacement interval (or age). Based on the TTF distribution as explained in section 8.2.3, the number of expected replacements, also called renewals, during T can be determined. Figure 30 shows the time from 0 (now) until T with the expected replacements of one component. In the figure, T is 11 years and the component has a expected lifetime of 1,5 year. Therefore, it is expected to replace the component 7 times during T, at the moments of the red arrows. = expected replacement T
0
FIGURE 30: NUMBER OF EXPECTED RENEWALS (REPLACEMENTS) DURING T
This expected number of replacements is of influence on the optimal policy parameter value of the time based maintenance policies. For example: if the block policy is applied with a replacement interval of 1 year, the probability that the component fails before it is replaced is very small, however the cost of spares and labour will be high since the component is replaced every year. On the other hand, with a longer replacement intervals of for example 2 years, the spares and labour costs are lower but the expected unplanned downtime costs are higher. This should be taken into consideration when determining the policy parameter value.
9.2.2. PROBABILITY OF MISSING DETERIORATION The policy parameter of periodic inspections and measurements is the inspection or measurement interval, which influences the probability of not inspecting or measuring during the deteriorated state and thus not replacing the component before a breakdown. Figure 25 showed the decrease of the condition of a component, where the Delay Time is defined as the time lapse from the first moment that deterioration is 34
inspectable until replacement cannot be delayed any longer (Christer & Waller, 1984). The moment that replacement cannot be delayed any more, is the moment of failure of the component. Figure 33 provides an illustration of the delay time of a component, on the time line of periodic inspections. As is shown in situation A, the delay time (a) is half of the time between inspections. The probability of not inspecting during the delay time is thus 50%. Situation B FIGURE 31: ILLUSTRATION OF PROBABILITY OF MISSING THE DELAY TIME shows an inspection interval that equals the delay time of the component. In that case, during the delay time an inspection will always be held and the probability of missing the deteriorated state is 0%. A short inspection interval has high labour costs for inspections and a small probability of missing a deteriorated state and therefore a small probability of unplanned downtime (and unplanned downtime costs). While a long inspection interval has less labour costs for inspections, although the probability of missing deterioration is high. Additionally, the periodic inspection policy prescribes condition expections with a fixed interval. In case it takes relatively long for a component before its delay time, this policy will prescribe many inspections, also during the time the components condition is sufficient. This is already mentioned as a disadvantage of this policy in section 7.2.3. In that case, it would be prefered to apply the sequential inspections policy, in which the time interval between inspections differ. Then, the first inspection can be postponed until the delay time is expected to start. From then on, more inspections could be scheduled to not miss the delay time of the component.
9.3.
REDESIGNED METHOD OF DETERMINING OPTIMAL PARAMETER VALUES
In the redesigned framework, for each possible policy of a MSC the optimal parameter value will be calculated, resulting the lowest expected Total Maintenance Costs (TMC). The TMC is defined as the maintenance related cost for a component, over the remaining lifetime of the system called T. Costs taken into account in the TMC are presented below:
Cost of planned and unplanned downtime. Heineken determined Cost of labour: the activities of maintenance experts (replacements, condition inspections and condition measurements) as well as the maintenance activities performed by third parties. Cost of spare components used for replacements. Cost of holding spare components in stock.
9.4.
EXECUTION OF ‘DETERMINE OPTIMAL POLICY PARAMETER VALUES’
In this step of the redesigned framework, for each possible maintenance policy as decided in the previous step, the optimal policy parameter value should be determined. This can be done according the following substeps per possible maintenance policy per MSC:
9.4.1.
SUBSTEP A: DEVELOP TMC CALCULATIONS
Develop the TMC calculations for each relevant maintenance policy, as selected in the step ‘Determine relevant maintenance policies’. Include the maintenance cost components as mentioned in section 9.3. In general, the TMC calculation is formulated like:
35
(
)
(9.1)
The formulas below explain how to calculate the costs used in the TMC formula above:
Costs of one planned replacement consist of 3 components: the labour costs of the maintenance department, the cost of the planned downtime and the cost of a spare part.
(9.2)
Costs of one unplanned replacement can be calculated similar as the cost of one planned replacement.
(9.3)
Cost of one inspection of the condition of the component. These are calculated by multiplying the rate of the maintenance expert by the expected inspection time, since inspections are executed by the maintenance experts of the maintenance department. (9.4)
Costs of one measurement of the condition of the component are calculated in a similar way. However, time required for one measurement includes registering the measured condition and time of evaluating and predicting the moment of failure. (9.5)
Heineken does not have a standard way of recharging the costs of holding spares in stock. It differs per technical system if it is relevant to take those into account and how those should be calculated.
Additionally, some technical systems may have other maintenance costs, i.e. fixed costs of service contracts with suppliers or costs for using a continuous monitoring system. Therefore, it is important to formulate the TMC formulas per technical system and take all different maintenance costs into account.
9.4.2. SUBSTEP B: GATHER REQUIRED INPUT FOR THE TMC CALCULATIONS To be able to calculate the TMC costs, the required information should be gathered. Several parameters have a fixed value for all components, like the hourly rates for planned and unplanned downtime and the costs of labour per hour. Other values, like the expected replacement time and expected unplanned downtime, differ per MSC but are fixed for each maintenance policy; i.e. if it takes 60 minutes to replace a chain by applying the block policy, it also takes 60 minutes to replace it if the age dependent policy is applied. Lastly, the information of applying a specific maintenance policy should be gathered. As explained in section 9.2, the value of the policy parameter influences the corresponding TMC of a maintenance policy. In this substep, the different possible policy parameter values and corresponding parameter values are also gathered.
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9.4.3. SUBSTEP C: DETERMINE OPTIMAL POLICY PARAMETER VALUE With the gathered information of substep B, the TMC of a policy for one MSC can be calculated. By calculating the TMC for different policy parameter values and its consequences (like a higher failure rate for long inspection intervals), the parameter value corresponding to the lowest TMC can be determined. This value and its corresponding TMC will be used as option for the MSC.
9.5.
CHAPTER SUMMARY
This chapter identified that Heineken currently does not have a method to determine the optimal parameter values, these are estimated by the maintenance experts, based on their experience. However, literature shows the relevance of finding the optimal parameter value, which is influenced by the expected number of replacements over time (period called T) and the probability of having unplanned breakdowns. For the periodic inspection policy and the periodic measurement policy, the interval of inspections and measurements are of great influence. Therefore, section 9.3 provided a redesigned method for Heineken to determine the optimal parameter values, based on the lowest Total Maintenance Costs (TMC). Lastly, it was explained how to execute the step â&#x20AC;&#x2DC;Determine optimal policy parameter valuesâ&#x20AC;&#x2122; according several substeps, that prescribe varying the parameter value and determine which value results in the lowest TMC.
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10. CONTENT OF THE STEP ‘DETERMINE MAINTENANCE CONCEPT’ This chapter explains the content of the step ‘Determine maintenance concept’; the fifth step of the second phase of the redesigned framework. Since the current method of determining the maintenance concept is already explained in section 8.1, this chapter will only explain the subteps of the execution of this step. Firstly, it will be determined which maintenance policy should be included in the maintenance concept for each MSC.This is explained in section 10.1. Then, it will be checked if the developed maintenance concept of the second phase of the redesigned framework fulfils all the objectives and restrictions that were set in the first phase of the redesigned framework. Section 10.3 explains the Greedy heuristic; a method to improve the developed maintenance concept. Lasyly, an example of the application of the Greedy heuristic is provided.
10.1.
SUBSTEP A: DETERMINE MAINTENANCE POLICY PER MSC
In the previous step of the redesigned framework, the lowest TMC corresponding to the optimal policy parameter value has been calculated for all possible maintenance policies of each MSC. For each MSC, the maintenance policy with the lowest TMC will be included in the maintenance concept. This composed maintenance concept is called the ‘initial solution’, which is the maintenance concept with the lowest TMC possible.
10.2.
SUBSTEP B: CHECK OBJECTIVES
In the step ‘Set objectives and restrictions’ of the first phase of the redesigned framework, two objectives are determined. It is decided what the maintenance budget for the technical system is and the maximal expected unplanned downtime is determined. In the following subsections is explained how to check if those two objectives are met.
10.2.1.
TOTAL MAINTENANCE COST OF THE DEVELOPED MAINTENANCE CONCEPT
As explained in section 8.4, a maintenance concept is constructed from the maintenance policy with the lowest costs for each MSC. Summing all Total Maintenance Costs of the MSC´s, the TMC of the maintenance concept can be calculated. The developed maintenance concept has the lowest possible TMC, based on the cost of labour, spare components and downtime, planned as well as unplanned (formula 10.1). (10.1)
10.2.2.
DIRECT MAINTENANCE COST RELATED TO THE MAINTENANCE CONCEPT
At Heineken, each production line has a maintenance budget per year, which is subdivided per technical system. The costs of downtime are not actually paid from that budget, only the cost of labour and cost of spare components. This part of the TMC is called the direct maintenance cost and can be calculated by the TMC minus the cost for (unplanned and planned) downtime. The direct maintenance cost of the maintenance concept should not exceed the objective of the maintenance budget as set during the first phase of the redesigned framework.
(10.2)
10.2.3.
EXPECTED UNPLANNED DOWNTIME RELATED TO THE MAINTENANCE CONCEPT
Besides the maintenance budget, another objective is related to the performance of the technical system: the maximal acceptable unplanned downtime. Therefore, the total expected unplanned downtime of the developed maintenance concept should be calculated. By summing up all expected unplanned downtimes
38
during T of all MSCs, which is the expected unplanned downtime per breakdown times the number of expected unplanned replacements of that component.
(10.3)
10.2.4.
CHECK OBJECTIVES OF THE MAINTENANCE CONCEPT
Via the calculations of the previous subsections, the direct maintenance cost and the expected unplanned downtime of the developed maintenance concept can be determined. If the direct maintenance cost exceed the budget restriction, for some MSCâ&#x20AC;&#x2122;s a maintenance policy with lower direct maintenance cost (and maybe higher unplanned downtime) can be chosen. If the expected unplanned downtime of the maintenance concept is too high according the set objectives, it possibly can be reduced by an investment in the maintenance activities with lower expected unplanned downtime. How to decide in which activities should be invested, is explained in the next section.
10.3.
SUBSTEP C: IMPROVE INITIAL SOLUTION ACCORDING OBJECTIVES
The Greedy heuristic, explained in section 10.3.1 and presented in an example in section 10.3.2, is a method that smartly determines which maintenance policies to adjust for which MSCs in order to fulfill the OPI-Nona objective within the budget restriction. This explanation and example are shown from the perspective that the expected unplanned downtime is too high and the maintenance budget is not yet exceeded.
10.3.1.
EXPLANATION GREEDY HEURISTIC
The greedy heuristic is a method that will search for the policy change that causes the highest reduction of unplanned downtime per euro should be chosen first. It is decided to use this heuristic over an exact method of calculation, since it is a fast and accurate method (Tan, 2011) and quite easy to understand. Additionally, Heineken can decide per step if the maintenance concept is sufficient or if it is worth it to add the next reduction. The steps of executing the Greedy heuristic are explained below based on the example given in section 6.5.1: Step 1: The developed maintenance concept consisting of the maintenance policies with the lowest TMC for each is set as initial maintenance concept. Its corresponding total direct maintenance cost and the total expected unplanned downtime are set as initial solution. Step 2: Calculate the expected unplanned downtime of each possible maintenance policy for all MSCâ&#x20AC;&#x2122;s. Additionally, calculate the direct maintenance cost for each maintenance policy, which are the TMC minus the cost for unplanned downtime:
(10.4) Step 3: Calculate the ratio of the difference of the expected unplanned downtime and the difference of the direct maintenance costs. This shows the expected reduction of unplanned downtime per extra euro invested in the maintenance concept. This ratio will help to fulfill the objective: decrease the expected breakdown time by investing more in the maintenance concept, with the lowest costs and within the budget.. (10.5)
39
Sort all ratios from high to low. Ratios equal or below 0 are not taken into account and can be deleted from the list, since those have a negative influence, i.e. it has higher costs for more unplanned downtime. Step 4: Take the highest ratio and replace the maintenance policy of the corresponding MSC in the initial solution by this one. Additionally, remove the initial and all other options regarding this MSC from the ratio list; the best ratio for this MSC is now selected and other policy changes are not relevant any more. Step 5: Calculate the new direct maintenance costs (formula 2) and the new expected unplanned downtime (formula 3) of this improved maintenance concept. If values are below acceptable, repeat Step 5; else, stop. If it is not possible to fulfil both objectives, this should be discussed with the Rayon technician.
10.3.2.
EXAMPLE GREEDY HEURISTIC
In this subsection, an example of the application of the Greedy TABLE 2: DATA EXAMPLE GREEDY HEURISTIC Heuristic as described in section 10.3.1 is provided. This example is based on three MSCs (item A, B and C) where for each MSC three maintenance policies are applicable (policy 1, 2 and 3). Data used in this example is shown in Table 2. Step 1: The initial maintenance concept includes the policies with the lowest TMC per MSC. This is: item A – policy 2, item B – policy 3, item C – policy 1; marked yellow in Table 2. Step 2: Calculate the direct maintenance cost as explained and the expected downtime per item per policy. Those numbers are shown in the table. The total direct maintenance cost of the initial solution during T is €27.283,33 and the total expected unplanned downtime during T equals 1000 min. The TMC of the initial solution is €36.716,66. Step 3: Calculate ratio of the difference in direct maintenance cost and expected TABLE 3: RATIOS EXAMPLE downtime for each policy with the initial solution policy, per item. Sort them from high to low. This list is provided in Table 3. Step 4: Take the highest ratio of the Table and exchange the policy from the initial solution. In this case, apply policy 2 instead of policy 1 for item C. Additionally, the second option from the table, also regarding item C, will be deleted from the list. Step 5: The TMC of this new maintenance concept is €36.765,83, the amount of direct maintenance costs during T equals €38.983,33 and the total unplanned downtime during T is expected to be 825 minutes. If this downtime is still not acceptable and Heineken is willing to invest more in the maintenance concept, Step 4 should be repeated; else, stop. Since the improvement of 0,03 minutes per invested euro is that low, it is decided to not improve the current maintenance concept and is the greedy heuristic stopped.
10.4.
CHAPTER SUMMARY
This chapter explained how to determine the maintenance concept, by firstly including the maintenance policy with the lowest TMC for each MSC. Then it is checked if the initial maintenance concept fulfils the objectives of maximal acceptable unplanned downtime and the maintenance budget. If not, the maintenance concept can be improved according the greedy heuristic, which is explained and presented in an example.
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11. EXECUTION PHASE 1 OF THE REDESIGNED FRAMEWORK TO THE PACKERS In section 1.3 the problem statement of Heineken is explained: the OPI-Nona of production line 7 is below target and should be increased by reducing the unplanned downtime of the packers. This chapter describes the execution of the first phase of the redesigned framework (Figure 16) according the steps of the preparation phase. The steps of the preparation phase are also shown in Figure 32 and will be discussed in order in the sections below.
11.1.
SET OBJECTIVES AND RESTRICTIONS
In the first step of the preparation phase, the objectives for the new maintenance concept will be determined: the required OPI-Nona increase and the maximal available costs. Additionally, the restrictions of the new maintenance concept are determined, together with the management of the particular technical system.
11.1.1.
Phase 1 Preparation maintenance concept development Set objectives and restrictions Gather information technical system Gather current maintenance concept Gather data breakdowns
Verify the gathered data Gather data of breakdowns of similar technical systems Gather data spare components Determine Maintenance Significant Components (MSC)
OBJECTIVES
The objective of the new maintenance concept of the packers is to increase the OPI-Nona performance of production line 7 against minimal costs within a predetermined maintenance budget. In the following subsections, the values of those objectives are determined.
FIGURE 32: PHASE 1 REDESIGNED FRAMEWORK
D ETERMINE OBJECTIVE OF THE INCREASE OF OPI-N ONA Table 4 shows the realized OPI-Nona per month and the breakdown time of the packers in that month. The minor stops (< 5 minutes) are not taken into account, since those are caused by fallen bottles and other small problems that are not maintenance related. As already explained in section 1.3, the OPI-Nona of a production line is influenced by many factors, not only the breakdown time of the packers. This causes that there is no direct relation between the downtime of the packers and the OPI-Nona in a specific month (as can be seen in Table 4). To define a objective for the OPINona increase, it is decided to use the average OPI-Nona performance and breakdown time over 2012, January to August. Based on the data provided in Table 4, the average OPI-Nona is 65,42%; 1,66% below the targetted 67,08%. The average breakdown time (unplanned stop of at least 5 minutes) of the packers of line 7 is 2.216 minutes per month. TABLE 4: REALIZED OPI-NONA AND BREAKDOWNTIME PACKERS, LINE 7
Month (2012) January February March April May June July August
Realized OPI-Nona line 7 69,96% 72,06% 73,14% 66,96% 64,36% 59,03% 59,59% 58,27%
Breakdowntime packers line 7 817 minutes 1628 minutes 1556 minutes 1418 minutes 1952 minutes 3943 minutes 3452 minutes 2959 minutes
There is no direct relation between unplanned downtime of a packer with the OPI-Nona. As was shown in Figure 4, there are 2 technical systems (the pasteurizer and the labellers) between the fillers and the packers. Therefore, the correlation between the breakdown time of the packers and the time the fillers are not able to produce since their output is calculated; resulting in a correlation in 2012 of 45%. 41
On average, the manned time of a packer is (480 minutes per shift, 15 shifts a week, 4 weeks per month), 28.800 minutes. Increasing production of the fillers with 288 minutes per month will increase OPI-Nona with 1%, if all other circumstances stay the same. As stated in the production at the filler is stopped by unplanned downtimes of the packers with a relation of 45%. That means that a decrease of unplanned downtime of 640 minutes per month will increase OPI-Nona with 1%. The objective of this research will be to increase the OPI-Nona with at least 1,66%. To reach that goal, the packers should have 1.062 minutes more production time per month. This results in a maximal allowed average breakdown time of (2.216 on average – 1.062 reduction of downtime) 1.154 minutes unplanned breakdown time per month; maximal acceptable 13.848 minutes unplanned breakdown time per year for both packers.
D ETERMINE MAXIMAL COSTS REGARDING THE MAINTENANCE CONCEPT Figure 33 provides an overview of the costs of maintenance activities over the last 6 years, including material costs and costs of activities by third parties. As can be seen, the total maintenance activity costs are about €100.000, - per year, for the last 3 years. At Heineken, the costs of modifications are included in the maintenance budget, as well as the costs of preventive and corrective maintenance costs. As explained in section 8.2.1, a modification will only be applied at a component that does not perform good enough with the best maintenance policy. In this research, a modification is in first instance not taken into account and it will be attempted to develop a maintenance concept for the MSCs with the mentioned maintenance policies of section 7.2. It is difficult to provide an exact budget for maintenance activities for the packers. However, the budget should be maximal €100.000,- per year; modifications included. € 120.000,00 Modification Preventive maintenance order Corrective maintenance order Total
€ 100.000,00 € 80.000,00 € 60.000,00 € 40.000,00 € 20.000,00 € 0,00 2006
2007
2008
2009
2010
2011
2012
FIGURE 33: COSTS REGARDING THE MAINTENANCE CONCEPT OF THE PACKERS OF PRODUCTION LINE 7
11.1.2.
RESTRICTIONS
Restrictions of the maintenance concept are:
Moments to execute planned maintenance are the stop days and the revision. Every 2 weeks, the packers are 6 hours available for maintenance activities. This time is required for cleaning activities of the fillers and determined by law. Revision is held every 2 years and has duration of 2 weeks. This is determined by the management of the production line and applied at all other technical systems of the production line. Maintenance personnel is available if requested on forehand. There are 4 maintenance experts and because of their expertise, it is preferred to have activities be executed by them. For easy or more regular tasks, execution by other maintenance personnel would be possible (10 persons).
42
11.2.
GATHER INFORMATION TECHNICAL SYSTEM
In this second step of the preparation phase, information is gathered of the technical system. For this research, information about the packers of line 7. APPENDIX I provides a schematic overview of one of the packers of line 7. These packers are similar to the packers of line 2, however, there are some differences. The packers of line 2 have a English measure, while the packers of line 7 are metric. Therefore, several components do have slightly different measures and are not equal. Unfortunately, only the components book of line 2 is updated in the past and mentions the modifications and component codes of the spares in stock. Personnel of line 7 does use this book for their packers, although the corresponding component codes are not correct. There exist numerous spare components books of the packers of line 7; however it is not clear which one is the most recent one that should be used. There is currently no good Bill of Materials (BOM) of the packers of line 7 and it should be composed by the project team (see section 11.8).
11.3.
GATHER INFORMATION OF THE CURRENT MAINTENANCE CONCEPT
In this step, all information of the current maintenance concept of the packers of line 7 is gathered. Section 2.2 described the current maintenance concept for the packers, which exists of inspection tasks divided over 6 orders for each packer that are implemented in SAP. Those inspection cards are easily assessable via SAP. It is discovered that the maintenance concept of the packers of line 7 is equal to the maintenance concept of the packers of line 2. Each maintenance task includes a reference to the components book of line 2 (which has other drawings and drawing-numbers than the components book of line 7).
11.4.
GATHER DATA OF BREAKDOWNS
In the fourth step of the first phase, data is gathered of the breakdowns of the technical system. Registration of breakdowns is available via the program MES, which provides the status of equipment and the failure-mode. A more precise description can be found in the notifications in SAP, although a notification is only made for a small percentage of the breakdowns. Besides, this information does only in a few cases provide clearly what the actual reason of a breakdown was; explanations are quite general (for example: ‘problems with component X’). A last source is the Break Down Analysis (BDA), which is an extensive analysis of one occurred breakdown of a technical system that took longer than 1 hour. However, this is not done for all breakdowns longer than 1 hour; of 2012, only 10 BDA’s are formulated for the packer while there were at least 40 breakdowns of at least 1 hour. Hence, there is not much reliable breakdown information available of the packers.
11.5.
VERIFY THE GATHERED DATA Breakdown
1% 6% 8%
In the previous step of the redesigned framework, data about the breakdowns is gathered. In this step, the data will be verified, to be sure and to understand the origin of the data.
8%
Change over / order 40%
Lack of input Production stop
As mentioned in section 1.3, all stops of the system longer than 5 minutes are registered in the category ‘Breakdown time’. Every stop longer than 5 minutes, needs to be explained by the operator of that shift in the program ‘MES Verpakken’. Analysing their explanations of causes of the long
Output jammed Unknown 37% FIGURE 34: BREAKDOWN CLASSIFICATIONS
43
stops, Figure 34 has been constructed, based on january until september of 2012 (this step was executed in september 2012). Figure 34 show the breakdown time registered by ‘Mes Verpakken’, divided per cause type provided by the operators It shows that 40% of the registered breakdown time it was a real breakdown according the operators. 37% of the time is pointed out by them as change over time. The other explanations lack of input (8%), production stop (8%) and output jammer (1%) are unexpected, since Mes Verpakken should be installed to automatically define this type of stops of the machine as output jammed, production stop or lack of input and it should not be registered as long stops. For 6% of the breakdown time, no explanation is given by the operator. The figure indicates that the data is not all correctly registered and errors in this registration result in unreliable information. The registered breakdown time does probable not indicate only downtime caused by breakdowns. Breakdowns of the packers are only a part of the time (based on Figure 34, only 40% are real breakdowns) the cause of downtime longer than 5 minutes, so the impact of improving maintenance by preventing breakdowns has probable less impact than hoped. That only 40% of the breakdown time are actual breakdowns may also explain the low correlation between the breakdown time of the packers and the jammed output of the fillers (section 11.1.1). However, for the first 8 months of 2012, the long stops of the packers are in total about 20.000 minutes i.e. 330 hours. The breakdowns are at least 40% of that time, based on operators’ explanations, which is 130 hours of downtime caused by breakdowns. Breakdowns are still a substantial part of the downtime. Although out of the scope of this research, together with the electricians of Heineken the errors and shortcomings of the breakdown registration of the packers of line 7 are solved as much as possible. Changes in MES Verpakken and the registration software and its results are provided in APPENDIX J.
11.6.
GATHER DATA OF BREAKDOWNS OF SIMILAR TECHNICAL SYSTEMS
In step 6 of the first phase of the redesigned framework, breakdowns data of similar technical systems is gathered. This can provide extra information of the life time of components. The two packers of line 2 and the packers of line 8 and 16 in Den Bosch are similar technical systems. Unfortunately, the shortcomings of the breakdown data as described in section 11.4 count also for the breakdown data of those similar technical systems. Additionally, breakdown data is registered differently per production line, with other breakdown names and states. Therefore, it is hard to compare the failures of similar equipment. Furthermore, Heineken Zoeterwoude has does not have access to the SAP data of other locations (like the one in Den Bosch). Aditionally, different locations use different spare components numbers and different maintenance concepts.
11.7.
GATHER DATA SPARE COMPONENTS
As extra source of information, in the seventh step is the data of spare components gathered. As stated in section 11.3 there did not exists a BOM for the packers of line 7. Neither the warehouse with spare components nor the maintenance department has a clear overview of which components can be used in the packers of line 7. Additionally, the spare components that are taken out of stock are not always allocated to the right functional location (each equipment on each line has a unique functional location number). Therefore, there is few and unreliable data from spare components available to use in determining the life time of a component.
44
11.8.
DETERMINE MAINTENANCE SIGNIFICANT COMPONENTS
The last step in the preparation phase is to determine the Maintenance Significant Components (MSCs) of the technical system. Only those components are taken into account in the remaining phases of the redesigned framework. Since the previous steps of the redesigned framework showed that there is not much reliable data of spare components and breakdowns. Therefore, together with the project team is decided that the MSC’s are all components from the following sources:
All components that are mentioned in the current maintenance concept; the SAP inspection cards and CILT list of the operators. All spare components in stock at Heineken, registered in SAP. All components that ever suffered from failure, since SAP is used (from 2006). All components ordered at the supplier for replacements. All components replaced or maintained during the revision.
Although the MSC-list is mainly based on sources from SAP in which this data has only been registered this data from 2006 on, it is expected by the maintenance experts that most maintenance significant components will have failed at least once in the last 6 years. APPENDIX K provides a list of all the maintenance significant components of the packers of line 7, categorized by assembly and subassembly, made by the project team of this research. This list will be used as the BOM of the packers and as a basis of the development of the maintenance concept.
11.9.
CHAPTER SUMMARY
This chapter discussed the execution of the first phase of the framework as shown in Figure 16. The goal of this first phase is to:
Determine the goals and restrictions of the maintenance concept. Despite of some uncertainties, it is determined that OPI-Nona should be increased by 1,66% and the maintenance budget per year available is maximal €100.000,- for both packers. Gather all information and data of the technical system required to develop a maintenance concept. Ideally, there would be enough reliable data to determine the Time to Failure (TTF) distriubtions of the components (as explained in section 8.2.3). However, the breakdown data was not extensive and complete enough for this intention. Thereby, the other steps that provide additional information that can help to establish the TTF distributions were executed. However, the data of similar technical systems and data of the use of spare components will not be feasible to determine the TTF distribution. To overcome this, required values will be determined in interviews with the maintenance experts from the maintenance department and the project team. Determine the list of Maintenance Significant Components. Due to unreliable and missing information and data, this took more time and effort than expected. However, a list of MSCs is constructed to be used in the second phase of the redesigned framework.
45
12. EXECUTION PHASE 2 OF THE REDESIGNED FRAMEWORK FOR THE PACKERS In Chapter 11, the execution of the first phase of the redesigned framework of the packers of line 7 is explained. In this chapter, the execution of the second phase will be discussed, in order of the executed steps as shown in Figure 35.
Phase 2 Development maintenance concept
Color breakdowns in ISO-metric
12.1.
COLOUR BREAKDOWNS IN ISO-METRIC
The first step of the second phase is to colour the breakdowns in the ISO-metric drawing with the whole team. This is one of the original steps of Heinekens framework, used to give the whole team more insight to the problem area and the impact of the problems.
Determine relevant maintenance policies for technical system Determine possible maintenance policies per MSC Determine optimal policy parameter values Determine maintenance concept
12.2.
DETERMINE RELEVANT MAINTENANCE POLICIES FOR
THE TECHNICAL SYSTEM In this second step of the development phase of the redesigned framework it is determined which of the maintenance policies from the overview in Figure 19 are relevant for the packers of line 7 (as explained in Chapter 7). Together with the Rayon technician, the Rayon manager and the project team, the maintenance policies shown in Figure 36 are determined to be relevant. The following subsections explain the decisions made. The following subsections will explain which maintenance policies are taken into account and which are not.
12.2.1.
Determine required spare components Cluster / harmonize maintenance activities Group maintenance activities
FIGURE 35: PHASE 2 REDESIGNED FRAMEWORK
MAINTENANCE POLICIES TAKEN INTO ACCOUNT FOR THE PACKERS
The following maintenance policies are taken into account for the packers of line 7:
The age-dependent maintenance policy based on calendar time is taken into account and could be relevant for components with a replacement time less than 6 hours. Then, a component can be replaced during a stop day. The block policy is relevant for all component with an replacement time longer than 6 hours, since those should be planned in a revision and cannot be replaced during a regular stop day. Additionally, for some components it can be less costly to apply the block policy instead of the age-dependent policy. If it is possible to inspect deterioration, inspection intervals are such that deterioration can be identified before it fails and if inspection time is relatively short, periodic inspections are an interesting policy. This policy will further be refered to as ‘periodic inspections’. If it is possible to measure the condition of a component, it can be interesting to register the measured data and monitor the deterioration of that component, to predict when it will fail and execute preventive maintenance before that moment. This type of maintenance requires an investment, since those technicians have to measure and monitor the condition of a component. This policy will be refered to as ‘periodic measurements’.
12.2.2.
MAINTENANCE POLICIES NOT TAKEN INTO ACCOUNT FOR THE PACKERS
The following (type of) maintenance policies are not taken into account in the succeeding steps, since those are not feasible for the packers of line 7.
M AINTENANCE POLICIES BASED ON CALENDAR TIME A huge investment (about €50.000,-) is required to link the production data system (MES Verpakken) to SAP to be able base the maintenance concept on the used production time and Heineken does not have the intention to execute that link. Alternatively, this could be solved by manually enter the data every week. However, this is 46
not a standard way of working at Heineken and would only be done for this maintenance concept. Heineken prefers to work according standards as mucht as possible and decided that policies based on production time should not be taken into account. Furthermore, the management of the production line expects the increase in production hours will only change for these 6 months and will not happen another time. Since it is expected that the increase in production hours is only once and the packers is always required in the production process (other than i.e. the six-pack equipment, that is only used when six-packs are produced), excluding the maintenance policies based on calendar time is acceptable for the maintenance concept of the packers. Production hours per week are roughly equal and the deterioration rate of components based on production hours will be converted to calendar time. I.e. 120 manned hours per week with about 110 production hours per week, thus a component with a lifetime of 10.000 production hours equals a lifetime (10.000 / 110) of 91 weeks.
S EQUENTIAL MAINTENANCE POLICIES The sequential maintenance policies in the categories: Time Based Maintenance, Condition Based Maintenance and Predictive Maintenance are not taken into account. Currently, there is not much documentation or standards; personnel needs to interpret too much and no clear rules are provided, whereby the conclusion of each person would differ. It is desired to work according standards and predetermined rules, what is not established by sequential maintenance policies since the maintenance expert should determine the next maintenance moment and this will again differ per person.
C ONTINUOUS MONITORING POLICIES There are no continuous monitoring systems available at the packer and therefore, the continuous monitoring policies of Condition Based Maintenance and Predictive Maintenance are not taken into account. Corrective Maintenance
Age-dependent policy Time Based Maintenance
Maintenance
Sequential preventive maintenance policy Block policy
Calendar time Production time Calendar time Production time Calendar time Production time
Continuous monitoring policy Preventive Maintenance
Condition Based Maintenace
Production time
Sequential inspection policy
Production time
Calendar time
Continuous monitoring policy
Standard classification Policies used in this research
Calendar time
Periodic inspection policy
Predictive Maintenance
Maintenance policies
Calendar time
Periodic inspection policy
Production time
Sequential inspection policy
Production time
Calendar time
FIGURE 36: MAINTENANCE POLICIES RELEVANT FOR THE PACKERS OF LINE 7 AND USED IN THIS CASE STUDY
12.3.
DETERMINE POSSIBLE MAINTENANCE POLICIES PER MSC
In section 8.4 has been explained how to execute this step. Firstly, a maintenance policy possibilities tree should be constructed according Step A (section 12.3.1). The second subsection will execute Step B, which consist of the application of the developed tree on all MSCs. 47
12.3.1.
STEP A: MAINTENANCE POLICY POSSIBILITIES TREE PACKERS LINE 7
For the relevant maintenance policies as shown in Figure 36, the maintenance policy possibilities tree for the packers is developed (presented in Figure 37). This possibilities tree provides questions that check which preventive maintenance policies are possible to apply next to corrective maintenance that is always applicable. As explained in section 8.2.2, preventive maintenance policies are only relevant for components with an increasing failure rate. This can be calculated with the failure rate function or hazard function (h(x)) (which is explained in section 8.2.2). However, the required data is not available at Heineken and the failure rate of a component will be determined by the maintenance experts, based on their experience. If a component has an increasing failure rate, Condition Based Maintenance is only applicable if the condition or deterioration of a component is detectable (measureable or inspectable). If not, Time Based Maintenance is the only preventive maintenance option. If deterioration is detectable, it is asked if measurement of the condition is possible, to determine if periodic measurement is also a possibility for that component. Additionally, the last question is if the FIGURE 37: MAINTENANCE POLICY POSSIBILITIES TREE PACKERS LINE 7 replacement takes less than 6 hours. If not, replacement is not possible on a regular stopday of the production line and should be executed during the revision. Then, it cannot be planned during the year and the agedependent maintenance policy is not applicable.
12.3.2.
STEP B: GO THROUGH THE TREE FOR EACH MSC
In step B, all MSCs should be put through the composed maintenance policy possibilities tree, to determine what maintenance policies are applicable at them. In this thesis, 3 components of the packers are used as an example in the execution of the steps, to give better insight in the content of all steps. Those three are expected to have a large influence on the breakdown time, by the maintenance experts based on their experience. The BOM position numbers refer to the BOM shown in APPENDIX K.
Cylinder (kettingspanner) (BOM position 1.2.1.1) Dozendoorvoerketting (BOM position 1.3.1) Tandriem (BOM position 4.1.2)
Each of these components is put in the maintenance policy possibilities tree and the answers are provided in Table 5. The cylinder as well as the dozendoorvoerketting has an increasing failure rate; hence the next question should be answered. Again, the answer is yes and as answer on the third question, the condition can be measured. Lastly, it is asked if the planned replacement time of the component takes less than 6 hours. The tandriem does have an increasing failure rate and deterioration is detectable. However, its condition cannot be measured, so that question is answered with No. Lastly, the question regarding planned replacement time is answered and it takes less than 6 hours. Concluding, all maintenance policies taken into account are technical feasible for the cylinder and the dozendoorvoerketting (corrective maintenance, age-dependent policy, block
48
policy, periodic inspections and periodic measurements). To the tandriem, all those policies except periodic measurements are applicable. TABLE 5: ANSWERS MAINTENANCE POLICY POSSIBILITIES TREE - 3 EXAMPLES
Increasing failure rate?
Deterioration detectable?
Measurement condition possible?
Planned replacement time < 6 hr?
Result
CM, Block, Age, CBM & Predictive DozendoorvoerCM, Block, Age, Yes Yes Yes Yes ketting CBM & Predictive CM, Block, Age & Tandriem Yes Yes No Yes CBM APPENDIX L provides the answers on the maintenance policy possibilities tree from Figure 37 for all MSCs of the packers of line 7. Cylinder
12.4.
Yes
Yes
Yes
Yes
DETERMINE OPTIMAL POLICY PARAMETER VALUES
Section 9.4 explained how to determine the optimal policy parameter value per possible policy of each MSC. The three substeps are discussed in the following sub sections.
12.4.1. STEP A: DEVELOP TMC FORMULAS FOR ALL RELEVANT POLICIES The following formulas are used to calculate the TMC of the maintenance policies taken into account for the packers, based on the explanation of the TMC in section 9.4.1. TMC C ORRECTIVE M AINTENANCE The TMC of the corrective maintenance policy are the costs per corrective maintenance activity multiplied by the number of breakdowns expected over the whole time horizon T. The number of breakdowns is approach by the expected number of renewals during T and the cost of a corrective maintenance activity. Hence: (12.1)
TMC B LOCK POLICY The block policy is a combination of planned and unplanned replacements. The component is replaced after every block interval; a planned maintenance activity. Additionally, if the component fails before the preventive replacement (time before the interval has ended), an extra maintenance activity is executed and unplanned downtime costs are caused. (12.2)
TMC A GE POLICY The TMC age policy cost is, like the block policy, a combination of planned and unplanned replacements. Planned replacements for the components that reach a specific age; unplanned replacements for the part of components that fail before that age and causing unplanned downtime.
49
(
)
(12.3)
TMC PERIODIC INSPECTION (C ONDITION B ASED M AINTENANCE ) The condition based maintenance policy with periodic inspections consists of planned and unplanned maintenance activities and cost for inspections. For this cost formula, it is assumed that inspections are perfect, meaning deterioration (the component is started to deteriorate and its condition is getting worse) is always discovered if the component suffers from it at the moment of inspection. The total inspection costs during the time horizon T are the number of inspections times its costs. The unplanned maintenance costs are caused by the failures that were not prevented as result of the inspections. The other failures could be prevented and for them only preventive maintenance costs are suffered. This is shown in the following formula: (12.4)
TMC PERIODIC MEASUREMENT (P REDICTIVE M AINTENANCE ) The cost of the predictive maintenance policy can be calculated in the same way as the periodic inspections. Additionally, the costs for purchasing measurement equipment are included, since some measures will require an investment in tools or techniques. (12.5)
APPENDIX M provides the mathematical formulation of the above TMC calculations and formulas to determine the input of those, as was explained in section 9.4.1.
12.4.2.
STEP B: GATHER REQUIRED INPUT FOR THE TMC CALCULATIONS
Determining the TMC the following input will be used:
The remaining lifetime of the system (T) is not precisely known. However, the management of the production line expects that it is reasonable that the technical system will be operated for the next 10 years. Therefore, T is set on 10 years. Cost of unplanned downtime. The current cost of downtime as used by Heineken are only based on the staffing costs of the operator, which is €566,- per hour for production line 7 (Heineken Savings List, 2013). Since the brewery at Zoeterwoude has overcapacity, they are able to produce the forecasted hectolitres which cover the fixed costs and overhead. Hence, the only costs not covered by unplanned downtime are the personnel costs of the operators that are present although not working. 50
Currently, Heineken does not calculate costs for planned downtime. The stop days are legally required cleanings of the fillers (as explained in section 2.2) and taken into account in determining the production targets, since the brewery at Zoeterwoude has overcapacity. The cost of one maintenance expert of the maintenance department are €60,- per hour. The cost of a spare component form stock can be identified via SAP. Costs of the spares not available in stock are estimated by the maintenance experts or requested at the supplier. The costs of holding spares in stock are not taken into account, since Heineken does not recharge those costs to the production lines. Additionally, it is not clear which components are used at which lines and in what proportion. There is no data available of replacements or downtimes, those values will also be estimated by the maintenance experts. As mentioned in section 9.2.1, the following variables should be determined: o Unplanned downtime. This is the expected time the technical system is down due to a breakdown of the component, including time to search for the broken component and expected waiting time for the maintenance expert (under the assumption that the maintenance experts have their regular capacity). Those times are based on the knowledge that production line 7 is a priority line in 2013, which means that breakdowns of line 7 are solved with priority over breakdowns of the other lines. It is not taken into account that the production line can loose this highest proirity and waiting time can increase in latter years. o Unplanned replacement time. This is the time a maintenance experts is working on the replacement of the broken component, including time to search for the spare component in stock or delivery time of a spare component. o Planned downtime. Downtime required to replace a component, in case the maintenance activity can be prepared. Mainly this is less than the unplanned downtime, since searching for the broken component is redundant. o Planned replacement time. The time of an maintenance expert required for the replacement of a component. Mainly, this is equal or less than the unplanned replacement time, since the spare component can be ordered and delivered before the replacement.
Other variables are calculated and/or determined in the following way:
Expected number of replacements. Section 9.2.1 explained how the number of expected replacements of a component can be calculated, based on its Time to Failure distribution. Unfortunately, as explained in section 11.4 and 11.7, the breakdown and spare component data of Heineken is not reliable and available data is not complete (of most spares only 2 or 3 replacements registered and it is not clear on which of the packers the part is replaced). As a consequence, it will not be possible to determine the time to failure distribution and deduct the other parameter values from this in this research. Therefore, in this case study, a meeting was held with the maintenance experts of the packers to determine the expected number of replacements during T and the probability it will fail before the planned replacement with a particular time interval. Christer and Waller (1984) developed a method to take the uncertainty of the length of the delay time(as explained in section 9.2.2) of a component per failure into account, based on the time to failure distribution of the component. However, there is no data available at Heineken about the delay time of components of the packer. Therefore, together with the maintenance experts is decided to assume an equal delay time for each component in each one component in all cases of failure. According this assumptions, the probability of not inspecting during the deteriorated state (and therefore having a breakdown causing unplanned downtime) equals (Christer & Waller, 1984): (12.6)
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This formula is also used to determine the probability of missing the deteriorated state while applying measurements, according the periodic measurements of predictive maintenance. The costs input for the TMC calculations of the three example components are given in Table 6. The calculations of those cost aspects can be found in the first section of APPENDIX N. TABLE 6: COSTS MAINTENANCE ACTIVITIES THREE EXAMPLE COMPONENTS
Costs of one planned replacement Costs of one unplanned replacement Costs of one inspection Costs of one measurement
12.4.3.
Cylinder € 146,21 € 955,21 € 35,€ 45,-
Dozendoorvoerketting € 1.909,55 € 4.173,55 € 60,€ 45,-
Tandriem € 269,24 € 2.627,57 € 10,-
STEP C: OPTIMAL POLICY PARAMETER VALUE OF POSSIBLE MAINTENANCE POLICIES
According the TMC formulas of step A and the information gathered in step B, the optimal value of the policy parameter should be determined. It is preferred to use the Time to Failure distribution to identify the policy parameter corresponding to the lowest TMC. However, the TTF distribution cannot be estimated because of a lack of data. In the following subsections is explained how the required values are determined and an example Therefore, the maintenance experts estimated the required values.
B LOCK AND AGE DEPENDENT MAINTENANCE POLICY FOR THE CYLINDER In a team meeting with the maintenance experts, several policy parameter values (the time interval) have been discussed with them and it was determined what the corresponding probability is of an unplanned breakdown before the preventive maintenance. Table 7 shows several intervals and the related TMC for the block policy and the age dependent policy. It is determined that the lowest TMC is obtained for both policies if an interval of 24 months is used. TABLE 7: POSSIBLE POLICY PARAMETER VALUES TBM POLICIES FOR THE CYLINDER
Interval 6 months 12 months 24 months 30 months
Probability unplanned breakdown 10% 25% 45% 75%
TMC Block policy € 4.914,62 € 3.950,13 € 2.970,27 € 3.570,47
TMC Age dependent policy € 4.622,20 € 3.584,60 € 2.641,30 € 3.131,84
P ERIODIC INSPECTIONS OF THE CONDITION OF THE CYLINDER As explained in section 9.2.2 and is shown in formula (12.6), the delay time and the inspection interval influence the probability of not inspecting during deterioration (and therefore missing the deteriorated state and causing an unplanned replacement). In the interview session the delay time per component was determined. For the cylinder the delay time equals 1 month. As a result, the lowest TMC is related to the inspection interval of 1 month (Table 8). TABLE 8: POSSIBLE POLICY PARAMETER VALUES CBM FOR THE CYLINDER
Interval 0,5 month 1 month 2 months 2 months
Probability missing deterioration 0% 0% 50% 67%
TMC CBM periodic inspection € 9.131,05 € 4.931,05 € 4.953,55 € 4.961,05
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P ERIODIC MEASUREMENT OF THE CONDITION OF THE CYLINDER Similar to the periodic inspections, the optimal policy parameter value of the periodic measurements can be determined. Figure 38 shows the different policy parameter values and their corresponding TMC. In order to measure the condition of the cylinder, an investment in measurement equipment is required of € 1.000,-. The TMC keeps decreasing when the interval increases (as can be seen in Figure 38). €7.200,00 TMC Periodic measurement
€7.000,00 €6.800,00 TMC
€6.600,00 €6.400,00 €6.200,00 €6.000,00 €5.800,00 0
50
100 150 200 250 300 350 400 450 500 550 600 650 700 750 800 Measurement interval (months)
FIGURE 38: TMC OF THE PERIODIC MEASUREMENT POLICY FOR THE CYLINDER
Since the TMC of periodic measurement is always higher than the TMC (as shown in Figure 38) of the other maintenance policies, it is decided to not take it into account in the next step and no optimal policy parameter is determined. For the dozendoorvoerketting and the tandriem, the optimal values for the different policy parameters are shown in Table 9. TABLE 9: TMC OPTIMAL POLICY PARAMETER VALUES OF THE THREE EXAMPLE COMPONENTS
Block policy Cylinder Dozendoorvoerketting Tandriem
€ 2.970,27 € 11.634,53 € 2.003,07
Age-dependent policy € 2.641,30 € 10.679,75 € 1.935,76
Periodic inspections € 4.931,05 € 4.953,55 € 1.873,09
Periodic measurements € 7.623,88 -
For all other MSCs, the optimal parameter values have also been calculated. Those are not separately provided in the thesis and are directly used in the TMC calculations. The result of the TMC of all MSCs can be found in APPENDIX O.
12.5.
DETERMINE MAINTENANCE CONCEPT
In this step, the maintenance concept is determined, as is explained in Chapter 10. Firstly, substep A is executed, in which is determined which maintenance policy should be applied at which MSC. Section 0 executes substep B, which evaluates the objectives. Lastly, substep C improves the maintenance concept such that it fulfils the OPI-Nona requirements for the available maintenance budget.
12.5.1.
SUBSTEP A: DETERMINE MAINTENANCE POLICY PER MSC
In this step, the TMC of each possible policy for all MSCs are compared, to determine which maintenance policy will result in the lowest cost for an MSC. For the three example components, an overview is provided in Table 10 where the lowest TMC of a component is printed bold. As a result, the following maintenance policies will be included in the maintenance concept: Cylinder – Age dependent policy; Dozendoorvoerketting – Periodic measurements; Tandriem – Periodic inspections.
53
In APPENDIX L, each MSC the TMC per possible maintenance policy is indicated. A red box indicates that that maintenance policy cannot be applied based on the results of the maintenance policy possibilities tree. The green box provides the lowest TMC for that component and will be included in the initial maintenance concept. TABLE 10: TMC PER POSSIBLE MAINTENANCE POLICY FOR THE THREE EXAMPLE COMPONENTS
Cylinder Dozendoorvoerketting Tandriem
12.5.2.
Corrective maintenance € 6.541,05 € 10.433,88 € 6.568,92
Block policy € 2.970,27 € 11.634,53 € 2.003,07
Age-dependent policy € 2.641,30 € 10.679,75 € 1.935,76
Periodic inspections € 4.931,05 € 8.373,88 € 1.873,09
Periodic measurements € 7.623,88 -
SUBSTEP B: CHECK OBJECTIVES
The objectives for the new maintenance concept are set in section 11.1.1: maximal 13.848 minutes of unplanned breakdown time per year for both packers, equalling 138.480. According the developed maintenance concept, the expected unplanned downtime per packer during T equals 70.264 minutes, which equals 140.527 minutes for both packers. Hence, the target is exceeded with 2.047 minutes of both packers during T. That means that one packer has 102 minutes expected unplanned downtime per year above target. The second objective stated that the direct maintenance costs (including costs of spare components and labour costs) should be maximal € 100.000,- per year; €1.000.000,- during T for both packers. According the developed maintenance concept, the expected direct maintenance costs equal €478.130,97; €956.261,94 for both packers together. Therefore, this objective is met and €43.738,06 of the budget remains.
12.5.3. SUBSTEP C: IMPROVE INITIAL SOLUTION ACCORDING OBJECTIVES Since the objective is not met and there is budget remaining, it is tried to improve the developed maintenance concept according the Greedy heuristic (as explained in section 10.3.1). According the objective, it is only relevant to change the initial maintenance policy for a maintenance policy with less expected unplanned downtime. For the cylinder, all maintenance policies are applicable and the age-dependent policy has the lowest TMC, that one is included in the initial solution. Table 11 presents the expected unplanned downtime and the direct maintenance costs, related to each maintenance policy (based on the two cylinders of the packer). The periodic measurements are not taken into account, since there is no optimal policy parameter of that policy. It shows that the periodic inspections has lower unplanned downtime than the age-dependent policy. For this policy, the ratio as mentioned in section 10.2.4 is calculated. TABLE 11: DATA GREEDY HEURISTIC CYLINDER
Expected unplanned downtime Direct Maintenance Costs Corrective maintenance 900 € 1.462,10 Block policy 540 € 2.046,94 Age-dependent policy 540 € 1.169,68 Periodic inspections 0 € 9.862,10 The ratio of the age-dependent policy and periodic inspections equals:
Table 12 shows the 10 highest ratios of all MSCs of the packer, in order from high to low. To improve the maintenance concept, the change of maintenance policies of the component with the highest ratio will be executed and the expected unplanned downtime and the direct maintenance costs are recalculated. 54
TABLE 12: RATIOS ALL MSCS PACKER, HIGH TO LOW
Component BOM location Initial policy New policy Ratio Flenslager 1.2.3. Age-dependent policy Periodic inspections 0,0833333 Flenslager 1.2.1.7. Age-dependent policy Periodic inspections 0,0772310 Klembus 1.4.3. Corrective maintenance Periodic inspections 0,0625000 Cylinder 1.2.1.1. Age-dependent policy Periodic inspections 0,0621231 Kettingwielen 1.3.1.3. Age-dependent policy Periodic inspections 0,0565043 Demper 5.3. Corrective maintenance Age-dependent policy 0,0547995 Curverol 1.2.2.4. Age-dependent policy Periodic inspections 0,0462796 Gaffel 1.2.1.2. Age-dependent policy Periodic inspections 0,0437669 Demper 5.3. Corrective maintenance Block policy 0,0410717 Flenslager 1.3.3. Age-dependent policy Periodic measurement 0,0404040 If the maintenance policy of the flenslager (the first component in Table 12) is changed from age-dependent policy to periodic inspections, the expected unplanned downtime is reduced with 600 minutes and the direct maintenance costs will increase with € 7.200,00, for both packers during T. The maintenance concept with this improvement has expected unplanned downtime of 139.927 (1447 minutes above target) and € 36.538,06 of the maintenance budget remains. By changing the maintenance policies of the first 4 components of the list of Table 12 (also the other flenslager, the klembus and the cylinder), the maintenance concept fulfils the objectives: the expected unplanned downtime equals 138.475 (5 minutes above target) and the direct maintenance costs are €985.708,12 (thus €14.291,88 of the budget remains).
12.6.
DETERMINE REQUIRED SPARE COMPONENTS
Section 3.3 explained the restrictions of this research, where is mentioned that it will be possible to add extra spare components to stock, however the spare components currently in stock cannot be removed from stock since those are also used for other technical systems. As section 11.7 explained, there is no clear overview which spare components are used on which tehcnical system. For the TMC calculations, the current spares in stock are taken into account. If the component does not have a spare in stock, the maintenance experts estimate what time it will require to get the technical system producing again (delivery time and replacement time). That time is included in the TMC of an unplanned replacement. It is assumed that before a planned replacement, the spare is already ordered and thus directly available for the maintenance activity. The costs of holding spare components in stock are out of the scope of this research (as mentioned in section 3.3), only the costs of the spare component itself is used in the TMC calculations. Although, it is recommended for Heineken to get an overview of the current spares in stock, the required stock levels for the execution of the maintenance concepts and to take the costs of holding spares into account in theTMC calculations. This recommendation is also mentioned in section 14.2.6.
12.7.
CLUSTER / HARMONIZE MAINTENANCE ACTIVITIES
In the previous step, the maintenance concept for the packer is developed. In this step, it is tried to combine maintenance tasks in order to save start-up costs and save costs of the maintenance budget, also called the direct maintenance costs (as explained in section 10.2.2). The assemblies mentioned in Table 13 are not easily reachable in the packer and require some time to reach the assembly, which will be defined in this research as the ‘start-up time’. This is taken into account in the replacement times and the inspection and measurements times. When maintenance activities of a specific component can be combined, it will save time of the maintenance experts and therefore labour costs, which 55
are included in the maintenance budget of a production line. The possible savings through clustering can be calculated according: (12.7) It is important to note that start-up time is required every time maintenance activities are executed. I.e. if 5 maintenance activities are clustered, it will save start-up time for 4 components, not for all 5. TABLE 13: ASSEMBLIES WITH SHARED START-UP TIMES FOR (PLANNED) REPLACEMENTS, INSPECTIONS AND MEASUREMENTS
Assembly BOM reference Start-up time Kettingspanner 1.2.1.1 – 1.2.1.9 30 minutes Dozenwip 1.2.2.1 – 1.2.2.4 30 minutes Anti-kantel mechanisme 2.3.1 – 2.3.7 20 minutes Demptafel 3.2.1 – 3.2.4 45 minutes The planned maintenance activities of the maintenance experts for the components of the kettingspanner of one packer are shown in Table 14. All savings through clustering are firstly calculated for one packer. TABLE 14: MAINTENANCE CONCEPT ASSEMBLY KETTINGSPANNER
Component
Maintenance policy
Interval
Maintenance Amount expert time per packer Cylinder Periodic inspections 1 month 35 minutes 2 Gaffel Age-dependent policy 12 months 60 minutes 2 Bus Age-dependent policy 24 months 60 minutes 2 Smoorventiel Age-dependent policy 120 months 40 minutes 2 Slijtplaat Age-dependent policy 48 months 60 minutes 4 Reactie arm Age-dependent policy 48 months 60 minutes 1 Flenslager Periodic inspection 12 months 45 minutes 6 Pen Age-dependent policy 48 months 40 minutes 1 Veer ring Age-dependent policy 12 months 40 minutes 2 For the cylinders and flenslagers, the maintenance activities of all pieces of that type of component can be clustered. If the periodic inspections of both cylinders are executed at the same moment, the start-up of one cylinder will be saved, which is 30 minutes per cylinder (as shown in Table 13). Determined in section 12.4.2, the labour costs of a maintenance expert are €1,- per minute. T is 10 years (also determined in section 12.4.2), hence the inspection of a cylinder will be executed 120 times during T. During T, combining the inspections of the cylinders saves:
The periodic inspections of the flenslagers can also be combined; this saves every year 5 times the start-up time, saving:
Additionally, the planned maintenance activities of the cylinders and flenslagers during T are shown in Figure 39. The cylinder (red) has inspections every month and the flenslager (blue) has an inspection every year. The figure shows the activities planned such that the inspection of the flenslager is executed on the FIGURE 39: PLANNED MAINTENANCE ACTIVITIES same moment as the inspection of the cylinder. Therefore, startCYLINDER AND FLENSLAGER
56
up time of the replacement of the flenslager can be saved: 30 minutes start-up time of the maintenance expert, 10 times during T: €300,-. Clustering can only be applied at the block policy and for periodic inspections and measurements, since with the age-dependent policy the moment of planned replacement will vary from the first unplanned replacement on. Table 15 shows for components of the kettingspanner that are maintained according the age-dependent policy the cost increase of applying the block policy instead of the age-dependent policy. For the gaffel, the replacement interval is 12; that means 120/12=10 replacements during T. In the kettingspanner of a packer there are 2 of those gaffels (Table 14). Table 13 shows that the start-up time for the kettingspanner equals 30 minutes. Hence:
TABLE 15: POSSIBLE SAVINGS PER PACKER THROUGH CLUSTERING COMPONENTS KETTINGSPANNER
Component Gaffel Bus Smoorventiel Slijtplaat Reactie arm Pen Veer ring
Block policy € 1.512,06 € 1.006,61 € 190,23 € 2.532,86 € 811,55 € 188,03 € 1.076,16
Age-dependent policy € 1.374,60 € 915,10 € 135,88 € 2.302,60 € 737,78 € 125,35 € 896,80
Extra costs block policy € 137,46 € 91,51 € 54,35 € 230,26 € 73,78 € 62,68 € 179,36
Possible savings € 600,€ 300,€ 60,€ 240,€ 60,€ 60,€ 600,-
Result € 462,54 € 208,49 € 5,65 € 9,74 -€ 13,78 -€ 2,68 € 420,64
Substracting the extra costs from the possible savings provides the result (calculated per packer during T). The results provided in Table 15 show that for 5 components of the kettingspanner it is beneficial to apply the agedependent policy and cluster the maintenance activities with the periodic inspection of the flenslager. By also clustering the planned replacements according the block policy of the gaffel, the bus, the smoorventiel, the slijtplaat and the veer ring with the periodic inspections of the flenslager, €1.107,06 per packer during T can be saved. Clustering of the maintenance activities of the components of the kettingspanner result in a total saving of €6.507,06 per packer; a saving of €13.014,12 of the maintenance budget for both packers during T. The clustering of the other three assemblies that can save start-up time through clustering of the maintenance activities (shown in Table 13) is provided in APPENDIX P. The savings through clustering per assembly are shown in Table 16. In total, by clustering the maintenance activities of those assemblies, €10.698,66 can be saved per packer which equals a saving of €21.397,32 of the maintenance budget of the packers during T. TABLE 16: SAVINGS THROUGH CLUSTERING PER ASSEMBLY DURING T
Assembly
Savings per packer
Kettingspanner Dozenwip Anti-kantel mechanisme Demptafel Total
€ 6.507,06 € 2.400,00 € 50,41 € 1.741,19 €10.698,66
Saving maintenance budget both packers € 13.014,12 € 4.800,00 € 100,82 € 3.482,38 €21.397,32
Concluding, by clustering the planned maintenance activities of the assemblies that require start-up time, €21.397,32 of the maintenance budget can be saved. This results in a required maintenance budget for this maintenance concept of (€985.708,12-€21.397,32) €964.310,80; €35.689,20 of the budget remains.
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12.8.
GROUP MAINTENANCE ACTIVITIES
In section 12.7, planned maintenance activities of an assembly that require start-up time are clustered, taken the time limit of a stop day into account, to save on the maintenance budget. In this step, the planned maintenance activities (the periodic inspections and measurements and the replacements according the block policy) are grouped to a so called maintenance card. A maintenance card includes all planned maintenance activities that should be executed at one technical system at one stopday. Each of maintenance card takes about 1 hour for administration and preparation of the maintenance department. Those costs are excluded from the maintenance budget, however, less maintenance cards save time for the maitnenance department. Because of clustering of maintenance activities as described in section 12.7, the required planned maintenance activities per interval are provided in Table 17. The maintenance activities for each 24 months or a multiple of that can be executed during the revision (2 weeks every 2 years), when te line is down for 4800 minutes and with 4 maintenance experts, there are 19200 minutes available for maintenance for both packers; 9600 minutes per packer. TABLE 17: REQUIRED TIME MAINTENANCE EXPERT PER INTERVAL PER PACKER
Interval Others 1 month 2 months 3 months 6 months 12 months 24 months 48 months 72 months 96 months 120 months
78 minutes 90 minutes 1355 minutes 120 minutes 440 minutes 260 minutes 3360 minutes 800 minutes 1440 minutes
Time Maintenance expert KettingDozenwip Anti-kantel spanner mechanisme 40 minutes
170 minutes 60 minutes 90 minutes
60 minutes 20 minutes 40 minutes 75 minutes
Demptafel
185 minutes 200 minutes
20 minutes
The exact planning of the planned maintenance activities of the block policy, periodic inspections and periodic measurements is provided in APPENDIX Q. For this planning, one maintenance card per month per packer is used. Resulting in 240 maintenance cards for the packers together during T. Since the smallest interval equals 1 month, this is the minimum number of maintenance cards possible.
12.9.
CHAPTER SUMMARY
In this chapter, the development phase of the redesigned framework is executed. Per MSC, it is determined which maintenance policies are applicable and what the optimal policy parameters for each possible maintenance policy are. Then, the Total Maintenance Costs (TMC) can be calculated, taking the costs of planned and unplanned downtime, of spare components and of labour into account. For each MSC, the maintenance policy with the lowest TMC is included in the maintenance concept. Then, it is checked if the maintenance concept fulfills the set objectives regarding the maximal acceptable expected unplanned downtime and the maintenance budget. The initial solution with the lowest Total Maintenance Costs did have too much unplanned downtime. By the application of the Greedy heuristic that maintenance concept is improved, with expected unplanned downtime of 138.475 minutes during (5 minutes above target) and costs within the maintenance budget. A last improvement step is executed by clustering and grouping the maintenance activities, in order to save an additional â&#x201A;Ź35.689,20.
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13. EXECUTION PHASE 3 OF THE REDESIGNED FRAMEWORK FOR THE PACKERS The last phase of the redesigned framework is the evaluation phase (Figure 40), which is executed in this chapter. Per section, one step is discussed.
13.1.
EVALUATE OBJECTIVES AND RESTRICTIONS
In this first step of the evaluation phase, the objectives and restrictions determined in the first step of the first phase of the redesigned framework (discussed in section 11.1) are evaluated. Firstly, the objectives will be discussed and in the second subsection, the restrictions.
13.1.1.
Phase 3 Evaluation developed maintenance concept
Evaluate objectives and restrictions
Ask permission for adjustments Adjust documents of the maintenance concept Check implementation in all documents
FIGURE 40: PHASE 3 REDESIGNED FRAMEWORK
EVALUATE OBJECTIVES
The maintenance concept improved via the Greedy heuristic results in an expected unplanned downtime of 138.475 minutes for both packers, during T. This is 5 minutes less than the objective. Additionally, the maintenance budget required for executing the maintenance concept as developed is, after clustering of the maintenance activities of the 4 assemblies shown in Table 13, â&#x201A;Ź964.310,80. I.e. a reduction of â&#x201A;Ź35.689,20 for a period of 10 years.
13.1.2.
EVALUATE RESTRICTIONS
The restrictions of the maintenance concept are that the planned downtime moments are the stop days (every 2 weeks 6 hours maintenance time) and the revision, which takes 2 weeks and is held every 2 years. Additionally, there is a capacity restriction since there are 4 maintenance experts with expert knowledge of the packers. The maintenance activities are planned according the planned downtime moments in section 12.8 for both packers. Concurrently, the maintenance restriction of 4 maintenance experts for both packers together is taken into account and the amount of time available per planned downtime moment is not exceeded. Hence, the developed maintenance concept accomplishes the restrictions.
13.2.
ASK PERMISSION FOR ADJUSTMENTS
In this step, the developed maintenance concept that fulfills the objectives and restrictions is proposed to the management team of the rayon. The rayon technician and rayon manager approve the developed maintenance concept and it can be implemented.
13.3.
ADJUST DOCUMENTS OF THE MAINTENANE CONCEPT
In the third step of the third phse, the documents in which the maintenance concept is saved are adjusted. This contains a new maintenance concept in SAP, new inspections on the CILT list of the operators and a BOM implemented in SAP.
13.4.
CHECK IMPLEMENTATION IN ALL DOCUMENTS
Lastly, it is checked if all documents regarding the maintenance of the packers are adjusted and the new developed maintenance concept is fully implemented. This maintenance concept is implemented according the feedback loop of the trigger system as shown in Figure 12 and will be reviewed after a revision and in case of low performance in 3 succeeding months.
13.5.
CHAPTER SUMMARY
This chapter executed the third and last phase of the redesigned framework, the evaluation phase. The maintenance concept as developed in the second phase of the redesigned framework was evaluated and when it was approved, it is implemented. Via the feedback loop, it will be continuously improved. 59
14. CONCLUSIONS AND RECOMMENDATIONS This last chapter will provide the conclusions and recommendations of this research. Additionally, the academic relevance is described and opportunities for further research are mentioned.
14.1.
CONCLUSIONS
In this research, a new maintenance concept for the packers has been developed, in order to answer the main research question as provided in the research design (section 3.2): Can Heineken Zoeterwoude increase the OPI-Nona of production line 7, through reduction of the breakdown time of the packers, by improving the maintenance concept of that technical system, taking a budget restriction into account? In section 11.1.1 is pointed out that it is difficult to exactly determine the maximal acceptable unplanned downtime for the packers in order to reach a particular OPI-Nona level, since OPI-Nona of a production line is influenced by many factors. In spite, the required OPI-Nona increase is estimated and used as objective. Additionally, a maintenance budget is determined for the maintenance activities of the packers. In this research, a maintenance concept is developed that is 5 minutes below the objective that the maximal acceptable expected unplanned downtime is 138.480 minutes for both packers during 10 years. The maintenance activities of this maintenance concept are realizable within the maintenance budget; the direct maintenance costs are expected to be â&#x201A;Ź964.310,80 for both packers during 10 years. Additionally, it should be mentioned that the research question is answered and the goals fulfilled without modifications, as discussed in section 11.1.1. In order to be able to answer the main research question, four research questions are investigated. Those are focused on the general method of the development of a maintenance concept: the general framework and tools that prescribe how to develop the maintenance concept. The four research questions are answered. 1.
Is the current control- and feedback loop of Heineken that updates the maintenance concepts working properly or could it be improved?
Currently there is no general guideline that determines if and when a maintenance concept should be reviewed or improved. Maintenance concepts are developed and implemented once and barely improved. I.e. only one maintenance task of the maintenance concept of the packers is changed in the former 6 years, while the packers suffer from a lot of breakdowns. A new feedback system is developed, shown in Figure 41. It prescribes to review a maintenance concept according one of teo causes. Firstly, a maintenance concept should be reviewed every two years, after the revision of the production line. During the revision many maintenance tasks are executed and it can be determined if policy parameters and maintenance policies are still optimal or could be improved. Secondly, the maintenance concept should be reviewed in case of low performance, measured by the Brewery Comparison System (APPENDIX C). If the target set for the maximal acceptable breakdown time FIGURE 41: TRIGGER MAINTENANCE CONCEPT IMPROVEMENT is exceeded in 3 successive months, the maintenance concept should be reviewed, such that the technical system will able to meet its targets. 60
2.
Via which framework is a maintenance concept currently developed and could it be improved?
This research investigated the current method of developing a maintenance concept. The Maintenance Optimization (MO) framework of Heineken is compared to the maintenance concept development frameworks of Gits (1992), Vanneste & Van Wassenhove (1995) and Wayenbergh & Pintelon (2002). Several shortcomings of the MO framework were discovered. Based on this literature, knowledge and experience at Heineken, the method has been redesigned. The redesigned framework is shown in Phase 1 Preparation maintenance concept development
Phase 2 Development maintenance concept
Phase 3 Evaluation developed maintenance concept
Set objectives and restrictions
Color breakdowns in ISO-metric
Evaluate costs of determined tasks (€ PM < € breakdown)
Gather information technical system
Color maintenance activities in machines ISO-metric
Evaluate required time and spare parts for tasks
Gather current maintenance concept
Determine relevant maintenance policies for technical system
Evaluate objectives and restrictions
Gather data breakdowns of the last year
Determine / evaluate maintenance policy and tasks
Ask permission for adjustments
Gather data breakdowns longer than 1 year ago
Determine possible maintenance policies per MSC
Adjust documents of the maintenance concept
Verify the gathered data
Determine optimal policy parameter values
Gather data of breakdowns of similar technical systems
Check implementation in all documents
Determine maintenance concept
Gather data spare components
Determine required spare components
Determine Maintenance Significant Components (MSC)
Cluster / harmonize maintenance activities
Phases framework
Removed steps
Original MO-steps
Replaced steps
Added steps
Changed content
Group maintenance activities
FIGURE 42: ADJUSTMENTS MO METHOD TO CONSTRUCT REDESIGNED FRAMEWORK (COPY OF FIGURE 15)
3.
Which maintenance policies are currently applied by Heineken and are there additional interesting policies that should be taken into account?
One aspect of the redesign is that more data is gathered and used to evaluate the performance of the technical system, via several newly added steps. As well, a step is added that prescribes to formulate specific objectives and restrictions that have to be fulfilled by the developed maintenance concept. Another change in the redesigned framework is that more maintenance policies are taken into account. Based on a literature review of maintenance policies (APPENDIX G), a general overview of several maintenance policies mentioned in literature is developed (shown in Figure 43), which contains more policies than currently used by Heineken. This overview is used in the newly added step ‘Determine relevant maintenance policies’ of the redesigned framework, that per technical system should determine which maintenance policies of the overview could be applicable at the technical system. 4.
What maintenance policy decision tools are currently used by Heineken and should those be redesigned, based on the literature review?
Additionally, the maintenance policy decision process has been changed. In the redesigned framework the technical feasible maintenance policy with the lowest Total Maintenance Costs is applied at a Maintenance Significant Component. In the current maintenance policy decision tools, Heineken did not take the costs of applying a maintenance concept into account. Then, it is checked if the developed maintenance concept fulfills 61
the objectives. If not, the maintenance concept can be improved according the Greedy Heursitic that is desribed and explained in this research.
Corrective Maintenance
Age-dependent policy Time Based Maintenance
Maintenance
Sequential preventive maintenance policy Block policy
Calendar time Production time Calendar time Production time Calendar time Production time
Continuous monitoring policy Preventive Maintenance
Condition Based Maintenace
Calendar time
Periodic inspection policy
Production time
Sequential inspection policy
Production time
Calendar time
Continuous monitoring policy Standard classification Maintenance policies
Predictive Maintenance
Calendar time
Periodic inspection policy
Production time
Sequential inspection policy
Production time
Calendar time
FIGURE 43: OVERVIEW MAINTENANCE POLICIES FROM LITERATURE (COPY OF FIGURE 17)
14.2.
RECOMMENDATIONS
This section provides the recommendations for Heineken regarding this research.
14.2.1.
IMPLEMENT CONTINUOUS IMPROVEMENT AND THE REDESIGNED FRAMEWORK
It is recommended to Heineken to change their vision regarding maintenance concepts to establish dynamic maintenance concepts experiencing continuous improvement instead of static concepts. Figure 41 shows the suggested triggers that define when to review and improve the maintenance concept of a technical system.
14.2.2. REVIEW CURRENT MAINTENANCE CONCEPTS The current maintenance concept of the packers exist of many inspection tasks. However, those tasks seem not to be reliable and this research showed that those are applied at components without an Increasing Failure Rate or a very short delay time. Additionally, inspections of the maintenance expert are relatively expensive and the lengthened lifetime often does not compensate the extra labour cost over a Time Based Maintenance policy. As a result, the new maintenance concept includes more Time Based Maintenance tasks and less inspection tasks than the current maintenance concept. Probably, current maintenance concepts of other technical systems are similar to the former maintenance concept of the packers it could be profitably to improve them. It is recommended to use the redesigned framework (Figure 42) with the steps explained in this research, like is done in this research in the case study of the packers of line 7.
14.2.3.
IMPROVE DATA REGISTRATION VIA SAP
As mentioned in section 11.4 and 11.5, the data to determine the Time to Failure distribution of a component is not registered and available. Firstly, Heineken does have a detailed information system that monitors and registers the performance of their equipment. However registered data is not always evident or tru; it would 62
be relevant for Heineken to verify the data they use. Secondly, Heineken Zoeterwoude does currently not have access in SAP to the data of Den Bosch, while both breweries use SAP, the same system. To increase the ease of gathering data in the first phase of the framework and therefore save time in those steps, it would be relevant to share the data. This will not only be of benefit for this framework, also for other projects or activities that require information of other breweries. Lastly, the data in SAP is incomplete: not all breakdowns are recorded as notification of SAP, spare components are taken from stock on wrong orders, BOMs do not exist etc. To execute the redesigned framework faster, easier and with a better result, accurate data would be a large benefit. Concluding, it is recommended to improve the data registration via SAP with clear rules and guidelines and to verify all data registered.
14.2.4.
MAINTENANCE CONCEPTS BASED ON PRODUCTION TIME
Another research direction for Heineken is to investigate the opportunities of maintenance concepts related to production time instead of calendar time. Estimated by the maintenance engineers, an investment of â&#x201A;Ź50.000,is required to connect the production information system to SAP. Additionally, all current maintenance concepts should be reviewed and redeveloped. This investment could be advantageous in case of varying production hours per week (like the change between 3 shifts and 5 shifts) and technical system that do not always produce when the line is operating (like the six-pack systems of line 7).
14.2.5.
MAINTENANCE ACTIVITY TYPE COMBINED WITH A MAINTENANCE POLICY
In section 7.2.6, an overview of maintenance acitivity types from literature is provided, although those are not further taken into account in this research, since the maintenance policy overview is already new for Heineken. However, a next improvement step for Heineken could include a maintenance activity type for each component, prescribing how to solve a breakdown or executed planned maintenance. Determining which maintenance activity type to apply can contribute to reach a specific goal, as explained in the benefits of applying maintenance activity types in section 7.4.2. Applying the maintenance activity types requires to review all current maintenance concepts and a new working procedure for the maintenance experts.
14.2.6.
ANALYZING REQUIRED SPARES IN STOCK
The redesigned framework constructed in this research is a guideline how to develop a new maintenance concept. The fifth step of the second phase of the redesigned framework is to determine the spare components required to execute the developed maintenance concept. The availability of spares influences the expected replacement time and therefore the performance of the maintenance concept. Additionally, there are costs related to keeping spares in stock. In this research, a restriction of Heineken was that the current spares should stay in stock, since those are also used for other technical systems and currently, Heineken has a budget for the stock of spares and the costs of holding spares in stock is not charged to production lines. However, it is recommended for Heineken to investigate their required stock levels and use the influence of spares and their related costs in the decision of maintenance policies and the development of the maintenance concept.
14.3.
ACADEMIC RELEVANCE
This research is a case study regarding maintenance in the sector of Fast Moving Consumer Goods, where a new maintenance concept is developed. A framework is composed in order to develop the maintenance concept. This framework is based on a literature review of several maintenance concept development frameworks mentioned in literature. Those are combined and compared and with the knowledge and experience of Heineken, a usable redesigned framework is developed.
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BIBLIOGRAPHY Aslam-Zainudeen, N., & Labib, A. (2011). Practical application of the Decision Making Grid (DMG). Journal of Quality in Maintenance Engineering, 17(2), 138-149. Chan, F. T., Lau, H. C., Ip, R. W., Chan, H. K., & Kong , S. (2005). Implementation of total productive maintenance: A case study. International Journal of Production Economics, 95, 71-94. Christer, A. H., & Waller, W. M. (1984). Delay time models of industrial inspection maintenance problems. Journal of the Operational Research Society, 35(5), 401-406. Gits, C. (1984). On the Maintenace Concept for a technical System, a Framework for design. Proefschrift: Technische Universiteit Eindhoven. Gits, C. (1992). Design of maintenance concepts. International Journal of Production Economics, 217-226. Labib, A. W. (1996). Integrated and interactive appropriate productive maintenance. Birmingham: PhD thesis, University of Birmingham, UK. Lewis, E. E. (1996). Introduction to reliability engineering. New York: Wiley. Mathew, S. (2004). Optimal inspection frequency. A tool for maintenance planning/forceasting. International Journal of Quality & Reliability Management, 763-771. McKone, K. E., & Weiss, E. N. (1998). TPM: planned and autonomous maintenance: bridging the gap between practice and research. Production and Operations Management, 7(4), 335-351. Moubray, J. (1997). Reliability Centered Maintenance. Oxford: Butterworth-Heineman. Nakajima, S. (1988). Introduction to TPM: Total Productive Maintenance. Cambridge, MA: Productive Press. Rausand, M. (1998). Reliability centered maintenance. Reliability Engineering and System Safety, 121-132. Shewhart, W. A. (1939). Statistical Method from the Viewpoint of Quality Control. Dover Books on Mathematics. Swanson, L. (2001). Linking maintenance strategies to performance. International Journal of Production Economics, 237-244. Tan, T. (2011). Course notes: Service Supply Chain for Capital Goods - Part I: Elementary Maintenance Models. Eindhoven University of Technology. Thomas, A., Barton, R., & Byard, P. (2008). Developing a Six Sigma maintenance model. Journal of Quality in Maintenance Engineering, 14(3), 262-271. Tsang, A. H. (2002). Strategic dimensions of maintenance management. Journal of Quality in Maintenance Engineering, 8(1), 7-39. Tsuchiya, S. (1992). Quality Maintenance: Zero Defects Through Equipment Management. Cambridge, MA: Productivity Press. Vanneste, S. G., & van Wassenhove, L. N. (1995). An integrated and structured approach to improve maintenance. European Journal of Operational Research, 241-257.
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Wayenbergh, G., & Pintelon, L. (2002). A framework for maintenance concept development. International Journal of Production Economics, 77, 299-313. Wayenbergh, G., & Pintelon, L. (2004). Maintenance concept development: a case study. International Journal of Production Economics, 395-405.
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FIGURES AND TABLES Below, a list of all Figures and al list of all Tables provided in this research is presented.
FIGURES Figure 1: Redesigned maintenance concept development framework ................................................................. IX Figure 2: Trigger start maintenance concept improvement ................................................................................... X Figure 3: Organizational chart Heineken Zouterwoude .......................................................................................... 1 Figure 4: Schematic overview line 7 ........................................................................................................................ 2 Figure 5: OPI-Nona Target and performance of production line 7, Jan-Aug 2012 .................................................. 3 Figure 6: Target and realization downtime indicators (in percentage of total available time), Jan-Aug 2012 ....... 3 Figure 7: Unplanned Downtime technical systems line 7, Jan-Aug 2012 ............................................................... 4 Figure 8: Development breakdown time packers line 7 ......................................................................................... 5 Figure 9: Costs of maintenance of the packers line 7, 2006 - 2012 ........................................................................ 6 Figure 10: Report outline ........................................................................................................................................ 9 Figure 11: Current process maintenance concept improvement ......................................................................... 11 Figure 12: New trigger start maintenance concept improvement ....................................................................... 12 Figure 13: Phases of the maintenance concept development framework ........................................................... 13 Figure 14: Maintenance optimization framework (Heineken) .............................................................................. 14 Figure 15: Adjustments of the Maintenance Optimization method to construct the redesigned framework ..... 17 Figure 16: Redesigned framework ........................................................................................................................ 17 Figure 17: Criticality matrix of Heineken ............................................................................................................... 20 Figure 18: Maintenance policies used by Heineken .............................................................................................. 22 Figure 19: Overview maintenance policies ........................................................................................................... 23 Figure 20: Maintenance activity types .................................................................................................................. 25 Figure 21: Maintenance policies used by Heineken .............................................................................................. 26 Figure 22: Maintenance activity types Heineken (green) ..................................................................................... 26 Figure 23: Maintenance activity types taken into account in this research (red) ................................................. 27 Figure 24: Maintenance policy decision tree of Heineken .................................................................................... 29 Figure 25: P-F curve Heineken .............................................................................................................................. 30 Figure 26: Bath-tub curve considering time-dependent failure rates (Lewis, 1996) ............................................ 30 Figure 27: Relation between PDF and CDF distribution ........................................................................................ 31 Figure 28: Redesign step Determine maintenance policy per component ........................................................... 32 Figure 29: General maintenance policy possibilities tree ..................................................................................... 33 Figure 30: Number of expected renewals (replacements) during T ..................................................................... 34 Figure 31: Illustration of probability of missing the delay time ............................................................................ 35 Figure 32: Phase 1 redesigned framework ............................................................................................................ 41 Figure 33: Costs regarding the maintenance concept of the packers of production line 7 .................................. 42 Figure 34: Breakdown classifications .................................................................................................................... 43 Figure 35: Phase 2 redesigned framework ............................................................................................................ 46 Figure 36: Maintenance policies relevant for the packers of line 7 and used in this case study .......................... 47 Figure 37: Maintenance policy possibilities tree packers line 7 ............................................................................ 48 Figure 38: TMC of the periodic measurement policy for the cylinder .................................................................. 53 Figure 39: Planned maintenance activities cylinder and flenslager ...................................................................... 56 Figure 40: Phase 3 redesigned framework ............................................................................................................ 59 Figure 41: Trigger maintenance concept improvement ....................................................................................... 60 Figure 42: Adjustments MO method to construct redesigned framework (copy of Figure 15) ............................ 61 Figure 43: Overview maintenance policies from literature (copy of Figure 17) ................................................... 62 Figure 44: OPI-NONA composition at Heineken (based on Brewery Comparison System, version 5) .................. 75 67
Figure 45: Criticality Matrix Packaging department Heineken Zoeterwoude ....................................................... 88 Figure 46: Decision Making Grid, based on Labib (1996) ...................................................................................... 90 Figure 47: Maintenance POlicy Decision Tree, based on Wayenbergh & Pintelon (2002) ................................... 90 Figure 48: Maintenance policy decision diagram, Wayenbergh & Pintelon (2004) .............................................. 91 Figure 49: Maintenance desicion locig diagram, Rausand (1998)......................................................................... 92 Figure 50: Maintenance policy decision diagram of the Stork Maintenance Management method (Stork Technical Services) ................................................................................................................................................ 93 Figure 51: Schematic lay-out packer 7 .................................................................................................................. 95 Figure 52: Planning maintenance activities during revisions .............................................................................. 116 Figure 53: Planning maintenance activities stopday ........................................................................................... 117
TABLES Table 1: Overview steps different maintenance concept development frameworks, categorized per general phase ..................................................................................................................................................................... 15 Table 2: Data example Greedy Heuristic ............................................................................................................... 40 Table 3: Ratios example ........................................................................................................................................ 40 Table 4: Realized OPI-Nona and Breakdowntime packers, line 7 ......................................................................... 41 Table 5: Answers maintenance policy possibilities tree - 3 examples .................................................................. 49 Table 6: Costs maintenance activities three example components ...................................................................... 52 Table 7: Possible policy parameter values TBM policies for the cylinder ............................................................. 52 Table 8: Possible policy parameter values CBM for the cylinder .......................................................................... 52 Table 9: TMC optimal policy parameter values of the three example components ............................................. 53 Table 10: TMC per possible maintenance policy for the three example components ......................................... 54 Table 11: Data Greedy heuristic cylinder .............................................................................................................. 54 Table 12: Ratios all MSCs packer, high to low ....................................................................................................... 55 Table 13: Assemblies with shared start-up times for (planned) replacements, inspections and measurements 56 Table 14: Maintenance concept assembly Kettingspanner .................................................................................. 56 Table 15: Possible savings per packer through clustering components kettingspanner ...................................... 57 Table 16: Savings through clustering per assembly during T ................................................................................ 57 Table 17: Required time maintenance expert per interval per packer ................................................................. 58 Table 18: Time Measurements OPI-Nona ............................................................................................................. 76 Table 19: Calculations Time definitions (Based on BCS, Version 5) ...................................................................... 76 Table 20: Targets and realization line 7 ................................................................................................................ 77 Table 21: Realization 2012 per month of the OPI-Nona targets ........................................................................... 77 Table 22: Phases in each maintenance concept development method ............................................................... 82 Table 23: Deliverables of the MAintenance concept development methods....................................................... 82 Table 24: Method per phase for each maintenance concept development method ........................................... 82 Table 25: Overview maintenance policy decisions from literature....................................................................... 94 Table 26: Assemblies ISO-metric drawing ............................................................................................................. 96 Table 27: List of all Maintenance Significant components .................................................................................... 98 Table 28: Answers maintenance policy possibilities tree packer 7 for all MSCs ................................................. 102 Table 29: Definition parameters APPENDIX M .................................................................................................... 106 Table 30: Fixed costs packers line 7, used as input for the TMC formulas ......................................................... 109 Table 31: Parameter values three example components packers line 7, used as input for the TMC formulas.. 109 Table 32: Costs maintenance activities three example components .................................................................. 109 Table 33: TMC for all possible maintenance policies per MSC ........................................................................... 110 Table 34: Maintenance concept dozenwip ......................................................................................................... 114 Table 35: Maintenance concept anti-kantel mechanisme .................................................................................. 114 68
Table 36: Possible savings per packer through clustering components anti-kantel mechanisme ...................... 115 Table 37: Maintenance concept demptafel ........................................................................................................ 115 Table 38: Possible savings per packer through clustering components demptafel ............................................ 115 Table 39: Required maintenance during revisions .............................................................................................. 116
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APPENDICES
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APPENDIX A LIST OF ABBREVIATIONS The table below provides an overview of all used abbreviations in this thesis. Abbreviation AM BCS BDA CBM cdf CFR CILT DFR DMC FMECA IFR KPI MIC MO MSC OPI OPI-Nona PDCA pdf RCM RT RtF TBM TMC TPM TTF TTR
Definition Autonomous Maintenance Brewery Comparison System Break Down Analysis Condition Based Maintenance cumulative distribution function Constant Failure Rate Cleaning – Inspecting – Lubricating – Tightening Decreasing Failure Rate Direct Maintenance Costs Failure Mode, Effect, and Criticality Analysis Increasing Failure Rate Key Performance Indicator Maintenance Insignificant Component Maintenance Optimization Maintenance Significant Component Operational Performance Indicator Operational Performance Indicator – No Order No Activity Plan – Do – Check – Act probability density function Reliability Centered Maintenance Rayon technician Run to Failure Time Based Maintenance Total Maintenance Costs Total Productive Maintenance Time To Failure Time To Repair
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APPENDIX B LIST OF DEFINITIONS The table below provides an overview of all definitions and their explanations used in this thesis. Definition Autonomous Maintenance
Breakdown Breakdown analysis Brewery Comparison System CILT-list
Condition-Based Maintenance Constant Failure Rate Cumulative distribution function Decreasing Failure Rate
Explanation Autonomous Maintenance is one of the pillars of TPM and is described as â&#x20AC;&#x2DC;the direct participation of production operators in the management of the processes & machines through effective cleaning, daily checks, lubrication, early detection of abnormalities and replacement of components or small repairsâ&#x20AC;&#x2122;. Unplanned downtime of a machine, that takes more than 5 minutes, between other states of the machine, like production, idle or no output possible. An analysis of a breakdown of a machine, which took longer than 60 minutes, to find the failure mode and implement a countermeasure to prevent this breakdown from occurring again. A reporting system used by all Heineken breweries around the world, to create internal reports using standardized definitions and calculation methods. List with tasks that operators have to execute and signoff in a defined period of time (each day/week/month) regarding maintenance of systems (cleaning, inspecting, lubricating and tightening). One of the maintenance policies used by Heineken. (Components of) components are inspected to check the condition of that part. Maintenance is only executed if the condition or performance of that component is below a specified criterion level. The change on failure of a component is constantly divided over time; each moment has the same change of a failure. Notated as F(t), which provides the probability a component fails at or before time t. Based on the corresponding probability density function. The change on failure of a component decreases over time; the older the component, the less change on failures.
Delay Time FMECA Increasing Failure Rate Maintenance activity type Maintenance concept Maintenance Significant Components Maintenance job Maintenance policy Manned Time Minor stop Performance Planned downtime Predictive Maintenance Probability density function
An extensive technique aimed at systematically assessing all the potential failures of a machine with its potential impact (criticality) on a human and/or the system. The change on failure of a component increases over time; the older the product, the more change it has to fail. Basic rule prescribing what (type of) maintenance to execute for a component. Collection of rules that describe maintenance: what maintenance tasks are required, when the tasks should be performed, how each task should be performed (criteria) and who should perform the maintenance task. All spare components in stock, all components currently maintained and components that ever failed or has been maintained. A combination of several maintenance tasks at the same maintainable unit. Basic rules prescribing when to maintain a component. The time there is action, no matter of what kind, with the line; operational utilization of the line, with man-machine interaction. Unplanned stop of a machine, that takes less than 5 minutes, between other states of the machine, like production, idle or no output possible. Total number good products produced in a specified period of time. Scheduled time the line is not producing, while a team is present. Predictive Maintenance is a maintenance policy based on the condition of a component. The measured condition per component is registered and monitored over time. This information is used to predict when a breakdown will occur and therefore, when to undertake action. Notated as f(t);provides the probability that a component fails at moment t.
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Reliability Centered Maintenance
Run to Failure Start-up time Technical system Time-Based Maintenance Time To Failure Unplanned Downtime
Maintenance methodology that aims to have a high reliability of the total system, by identifying the most appropriate maintenance policy for a specific component, based on the expected consequences of a stop. Different maintenance policies are Run to Failure, Time-Based Maintenance and Condition-Based Maintenance. One of the maintenance policies used by Heineken. There are no preventive maintenance activities executed for that component; it is used until it fails, in that case, it is repaired or replaced. In case an assembly existing of several components is not easily reachable in the packer, the shared time it requires to reach it is defined as â&#x20AC;&#x2DC;start-up timeâ&#x20AC;&#x2122;. A group of physical components that together fulfill one specific function. One of the maintenance policies used by Heineken. (Components of) components are replaced or returned to their original condition after a fixed period (calendar time or production hours). Time to failure is the time between two successive failures of one component type. Time that all resources needed for production except the machine are available; production is not possible due to internal problems of that machine.
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APPENDIX C TARGETS BREWERY COMPARISON SYSTEM To measure the performance of breweries and their production lines, Heineken uses the Brewery Comparison System (BCS); a reporting system to create internal reports according standardized definitions and calculation methods. The main key performance indicator (KPI) of BCS is OPI-Nona, which is the abbreviation of Operational Performance Indicator – No Order No Activity. Figure 44 gives insight in the composition of OPINona and other KPI’s.
FIGURE 44: OPI-NONA COMPOSITION AT HEINEKEN (BASED ON BREWERY COMPARISON SYSTEM, VERSION 5)
The time basis, called Total time in Figure 44, is calculated as total hours in a period of time (day, week, month); this is a fact. The production line measures the red definitions shown in Figure 44, to calculate the other terms, written in black. Table 18 defines the measured times of a production line and provides examples of those times, and Table 19 shows an overview of the calculations of the definitions written in black and explains them. The purple definitions are also calculated, based on the amount of production and the blue term ‘Speed losses’ is the rest value of the calculation. The main KPI OPI-Nona is the time theoretically needed to produce the produced orders (based on the production norms), as percentage of the effective working time. It can be calculated as: (C.1) All time measurements and calculations regarding OPI-Nona (mentioned in Figure 44), are based on the fillers. The fillers have the lowest production rate of all machines in the line; their maximal production per hour is 80.000 bottles/hour, while for example the packers produce at least 3600 boxes/hour, which equals 86.400 bottles/hour. With the formulated time definitions (Figure 44), the main KPI OPI-Nona can be calculated, as the percentage of the theoretical required time to produce the produced orders of the effective working time. For each line, Heineken set a performance target, defined in OPI-Nona percentage. Besides this percentage, the rest of the effective working time (as explained in Figure 44 the effective working time exists of several components) is divided in other categories with each a target as percentage of the effective working time. All these targets and realization are based on the fillers. The targets and the realization of them in 2012 of line 7 are given in Table 20. 75
TABLE 18: TIME MEASUREMENTS OPI-NONA
Name Unused Time
Time Measurements Definition No activities at the line, not for production or maintenance. 'Lights out, door closed.' E.g. weekends and Christmas
Non Team Maintenance Time NONA Time (No Order, No Activity) Planned Downtime
Maintenance executed by others that the operator teams E.g. maintenance by 3th parties or the maintenance department No Order, No Activity. All resources available to produce, but no orders to produce. Operators do other jobs (like cleaning) they would not do if there was an order to produce. Scheduled time the line is not producing, while a team is present. E.g. cleaning, planned maintenance and meetings.
Change-over time
A special type of planned down time. This is registered separately to keep an eye on change-over times.
Breakdown
Defined as: equipment stoppage (> 5 minutes) that involve technical repair. Measured as: unplanned downtime longer than 5 minutes (not always technical repair required).
External stop
Interruption of the packaging line, with their root cause outside control of the packaging team. E.g. no beer, no external transport etc.
Minor stops
Every stoppage less than 5 minutes that causes downtime in the equipment. E.g. a bottle that is fallen and causes a stop of the machine.
TABLE 19: CALCULATIONS TIME DEFINITIONS (BASED ON BCS, VERSION 5)
Name
Time Calculations Definition Total time in a period.
Total Time
= Actual hours in a specific period of time. Manned Time
Time there is action, no matter what, with the line. = Total Time - Unused Time
Operating working Time Effective working Time
Time operator team is present and doing their job. = Manned Time - Non Team Maintenance Time Time operator team is executing product orders and other planned jobs. = Operating working Time - NONA
Available production Time Operational Time
Time operator team is scheduled to produce orders. = Effective working Time - Planned Downtime - Change-over time Time the machine should be able to operate, according to the schedule. = Available production time - Breakdown
Production Time
Time the machine is actual producing. = Operational time - Minor stops - Speed losses
Theoretical production Time Reject & Rework
Speed losses
Time the line produced based on norm cycle times (boxes/hour). = Produced boxes / Norm boxes per hour Any product removed from the line between the filler and the palletiser, due to e.g. low fills, missing caps, broken bottles etc. = Rejected boxes / Norm boxes per hour This category fills the gap between all times measured and calculated based on production data. (Can be negative.) = Operational time - Production time - Minor stops
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TABLE 20: TARGETS AND REALIZATION LINE 7
OPI-NONA Planned down time Change over time External stops Breakdown time Speed losses & minor stops Reject & Rework
Target 2011 70,00 % 8,13 % 0,42 % 0,00 % 8,96 % 12,08 % 0,42 %
Target 2012 67,08 % 8,96 % 3,96 % 0,42 % 8,75 % 10,42 % 0,41 %
Realization 2012 (- Aug) 65,42 % 10,77 % 1,91 % 0,32 % 10,50 % 10,77 % 0,31 %
Difference 2012 - 1,66 % + 1,81 % - 2,05 % - 0,09 % + 1,75 % + 0,36 % - 0,10 %
Table 20 shows that the OPI-Nona target of this year is 67,08%. However, the realized target until august is on average only 65,42%. Other remarkable aspects are the exceeded targets of planned down time and breakdown time. This is caused by a the exceeded percentage of 3 losses: Planned downtime (+1,81%), Breakdown time (+1,75%) and Speed losses & minor stops (0,36%) at the filler. Table 21 shows the realizations of all categories, per month; the bolt numbers are excedings of the targets. Especially in the last months, the OPI-Nona target is not realized caused by the relatively high realized planned downtime and high breakdowntime. In order to increase the OPI-Nona of production line 7, the planned downtime, breakdown time and speed losses & minor stops could be reduced. TABLE 21: REALIZATION 2012 PER MONTH OF THE OPI-NONA TARGETS 2012 OPI-NONA Planned down time Change over time External stops Breakdown time Speed losses & minor stops Reject & Rework
Target 67,08 % 8,96 % 3,96 % 0,42 % 8,75 % 10,42 % 0,41%
January 69,96 % 8,64 % 1,25 % 0,00 % 10,45 % 9,26 % 0,44 %
February 72,06 % 8,46 % 2,09 % 0,63 % 7,46 % 8,90 % 0,39 %
March 73,14 % 7,16 % 1,04 % 0,18 % 7,81 % 10,49 % 0,18 %
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April 66,96 % 9,41 % 0,82 % 0,17 % 10,72 % 11,03 % 0,89 %
May 64,36 % 10,25 % 2,43 % 0,21 % 10,03 % 13,00 % -0,27 %
June 59,03 % 12,27 % 1,84 % 0,84 % 13,80 % 11,89 % 0,34 %
July 59,59 % 13,77 % 3,92 % 0,32 % 11,87 % 10,04 % 0,50 %
August 58,27 % 16,17 % 1,87 % 0,24 % 11,85 % 11,58 % 0,03 %
APPENDIX D LITERATURE REVIEW MAINTENANCE CONCEPT FRAMEWORKS D 1. MAINTENANCE CONCEPT DEVELOPMENT METHODS The goal of this research is to improve the maintenance concepts of the packers of line 7, to reach higher availability of the machines for minimum costs. In literature, numerous methods for the development and improvement of maintenance concepts are described. This appendix provides an overview of several methods and evaluates them for the application at this case of Heineken.
D 1.1. TOTAL PRODUCTIVE MAINTENANCE Total Productive Maintenance (TPM) is a maintenance methodology, developed in Japan and introduced by Nakajima (1988). Seichii Nakajima was vice-chairman of the Japanese Institute of Plant Maintenance (JIPM), who in 1971 defined TPM as: “TPM is designed to maximize equipment effectiveness (improving overall efficiency) by establishing a comprehensive productive-maintenance system covering the entire life of the equipment, spanning all equipment-related fields (planning, use, maintenance, etc.) and, with the participation of all employees from top management down to shop-floor workers, to promote productive maintenance through motivation management or voluntary small-group activities.” (Tsuchiya, 1992, p. 4). TPM is based on the PM (preventive maintenance) approach, which was used by many Japanese companies. It is an improvement of the PM approach, because PM still caused support and maintenance problems. (Chan, Lau, Ip, Chan, & Kong , 2005). Nakajima (1988) states that the improvement of the TPM strategy is found in ‘Total’ (T of TPM) and is threefold:
Total effectiveness is represented in the overall goal of TPM; to minimize the number of breakdowns and to work as efficient and profitable as possible. Total maintenance system refers to the goal to have ‘maintenance-free’ equipment. Total participation in a company is essential for a solid implementation of TPM. That includes commitment from everybody, from top-management to operators. Autonomous maintenance (will be explained in the next section) is one of the features of TPM that supports this segment.
TPM is a well-known and widely used management principle which is broadly discussed and described by various authors, with all their own point of view or explanation of aspects of the method. One of the more comprehensive explanations is given by Wayenbergh and Pintelon (2002). They describe the TPM method in five main points:
TPM’s goal is to maximize the efficiency of equipment and to improve the overall effectiveness of the equipment. Effectiveness can be defined as ‘doing the right things’ and is mainly calculated by dividing the available production time by the manned time. TPM provides a complete productive maintenance program for the entire life of equipment, including maintenance prevention, preventive maintenance, and maintenance related to improvements of equipment. TPM requires the participation of equipment designers, equipment operators, and maintenance department workers and is implemented on a team basis. TPM involves all levels of an organization; all employees, from the top management to the production floor operators. TPM implements productive maintenance and promotes autonomous maintenance for small groups.
Swanson (2001) gives another interesting view on the TPM method. Swanson appoints TPM as an aggressive strategy, which is defined as a strategy that focuses on the actual improvement of the design and the function of equipment. That differs from the more traditional reactive or proactive strategies, which focus on descriptive and preventive maintenance. 78
While developed as a maintenance strategy, nowadays TPM is mostly seen as a strategy that comprises more than only a maintenance policy. Other important goals of TPM are the improvement of other manufacturing performance measures like cost, quality, delivery, flexibility, and innovativeness (McKone & Weiss, 1998). When TPM was developed, the abbreviation was translated as Total Productive Maintenance. However, today it is more and more translated as Total Productive Management, since it has not only influence on the maintenance strategy of a company. So on the one hand, TPM is more than only a maintenance concept; on the other hand, TPM is incomplete as maintenance concept since it does not provide clear rules how to perform maintenance. It is seen as a management strategy which affects all different segments in a company with some guidelines for improving the maintenance concepts (Wayenbergh & Pintelon, 2002). This view on TPM is shared by Heineken. According to Frank Rhomer (Heineken) in Process Control, Heineken translates TPM as ‘Total Productive Management’, to emphasize that the TPM principle is not limited to the production units only (Van Ede, 2010). Therefore, Heineken uses TPM as strategy and applies the more specified maintenance strategy RCM.
D 1.2. RELIABILITY CENTERED MAINTENANCE Moubray (1997) developed an extension to the basic Reliability Centered Maintenance (RCM), called RCM II, generally applicable in industry, where RCM was originally designed for the aircraft industry. RCM exists of the following seven steps, which each are questions that need to be answered:
What is the item supposed to do and what are its standards? In what ways can it fail to provide the required functions (functional failure)? What are the events that cause each failure (failure modes)? What happens when each failure occurs? In what way does each failure matter (criticality)? What systematic task can be performed proactively to prevent or diminish, to a satisfactory degree, the consequences of the failure? What must be done if a suitable preventive task cannot be found?
In short, RCM determines which functions should be performed, identifies all possible causes of all possible failures, determines how important each failure will be and then determines what maintenance should be performed (also called FMECA). RCM starts from nothing and develops a whole new and very broad maintenance concept. Wayenbergh and Pintelon (2002) state that the biggest disadvantage of RCM is the complexity and extension of the method, which causes a high price for the application of the method. Only in high-tech/high-risk industries it is required to apply an approach like RCM or RCM II; for general industries it is mostly too expensive and time-consuming. In the first chapter of this proposal was mentioned that Heineken used to apply the RCM methodology to develop maintenance concepts for their equipment. However, since the methodology of RCM is timeconsuming and does not make use of existing maintenance concepts and gathered data about failures and maintenance activities, Heineken developed their own methodology to improve maintenance concepts, which will be explained next.
D 1.3. MAINTENANCE OPTIMIZATION As mentioned before, Heineken does not use the RCM method. They developed their own method to improve current maintenance concept, which is called Maintenance Optimization (MO). This method is explained in section 5.2. In short, this maintenance methodology pays only attention to components that are mentioned in the current maintenance concepts and components that failed the last 12 months. The current maintenance concepts as well as the breakdowns are evaluated to compose a new maintenance concept. This is evaluated, regarding demand for resources and costs and hereafter the new concept is implemented. 79
D 1.4. FRAMEWORK GITS Gits developed another framework for the development of maintenance concepts, what exists of 7 steps (Gits, 1992) distinguishes 3 phases (Gits, 1984). Below, the different phases with their associated steps are described. Phase 1: technical analysis of the system In the first phase, all information required for the execution of the following steps is gathered:
Failure behavior analysis; information about the failures and their underlying causes. Failure consequence analysis; the consequences of each failure are identified. Hardware structure analysis; information about the accessibility of the components.
Phase 2: generation of maintenance rules The second phase is the design phase where maintenance rules are determined. The designing process is decomposed in several steps: Step 1: Qualifying maintenance initiations. For each component, the optimal maintenance policy is determined according to a decision tree developed by Gits. This diagram has three possible maintenance policies: failure maintenance, use based maintenance and condition based maintenance. Step 2: Specifying maintenance operations. In this step, concrete maintenance tasks are formulated regarding the maintenance policies as determined in step 1. Step 3: Limiting maintenance intervals. For each maintenance tasks, the maximal time interval the tasks should be performed is determined. Step 4: Clustering maintenance operations. This step creates efficient combination of individual maintenance tasks into maintenance clusters with the same setup moment. Step 5: Harmonizing maintenance intervals. The setup of maintenance clusters are further combined, to save even more on setups. Note: Step 4 and 5 may be performed simultaneously. Step 6: Grouping maintenance operations. The maintenance clusters are allocated over time, such that the maintenance activities are smoothed over time. Phase 3: determination of the maintenance concept Third and last, this phase is a controlling phase that verifies if the developed rules meet the criteria. Step 7: Evaluating maintenance rules. Evaluation of the developed maintenance concept, in terms of:
Appraising maintenance cost. Evaluation of the costs associated with the maintenance concept and compared to the set norm. Characterizing maintenance demand. Evaluation of the performance of the developed maintenance concept, regarding the preference for preventive maintenance. Classifying preventive maintenance. Evaluation of the performance of the developed maintenance concept, regarding the demand for maintenance.
The framework of Gits uses available information of the performance of equipment in the past. Based on this information, one of the three maintenance policies is assigned to components and maintenance tasks are described. The framework is especially focused on the planning of activities, since 4 of the 7 steps concern the maintenance intervals and the efficiently planning of all maintenance activities. In the last step, the developed maintenance concept is evaluated regarding maintenance costs and demand. There are no rules specified about continuous improvement of the maintenance concept; the concept is developed and implemented, there are no steps about gathering feedback and optimizing the concept. 80
D 1.5. FRAMEWORK VANNESTE & VAN WASSENHOVE Vanneste and Van Wassenhove (1995) developed a framework for the setup of a continuous improvement system for maintenance management. Their approach exists of 8 phases, as explained below, which form a closed loop that creates a program to continuously improve the maintenance concepts.
Obtain a clear picture of the current factory performance. Determining the problem area, set goals and gather information about the current situation (maintenance and performance). Analyze quality and downtime problems. Structuring problem and their root cause, to define the location of major downtime problems. Analyze effectiveness of alternative solutions to (major) problems. Generate solutions and execute a cost-benefit analysis of each solution. Analyze efficiency of maintenance procedures. Trade-off between cost and benefits to get insight in the optimal actions, regarding its costs and impact. Plan actions. Select which actions should be taken, based on the information of step 4. Implement actions and gather data. Implementation of the concept and to gather information about the performance after implementation. Monitor actions and process data. If necessary, determine follow-up actions. Adapt plans or information procedures in case of undesired deviations. Go to phase 1.
Shortly, this framework specifically set goals about maintenance and performance and gathers information of the current downtime problems. Steps 3, 4 and 5 determine maintenance tasks, based on a cost-benefit analysis of all possibilities. However, no rules or guidelines of determining possible solutions are provided, like possible maintenance policies. The last steps define how to improve the developed maintenance concept and to gather required information to make improvement decisions.
D 1.6. FRAMEWORK WAYENBERGH & PINTELON Wayenbergh and Pintelon (2002) evaluated a number of frameworks to design maintenance concepts and developed their own framework. It exists of the following steps:
Start-up and identification of objectives and resources. Objectives for the maintenance concept and the requirements to meet the objectives are set. Identification of the Most Important Systems (MISs). To reduce complexity, the MISs (breakdown with consequences for safety or environment, bottlenecks, high repair costs etc.) are identified. Criticality analysis. The Most Critical Components (MCCs) of the MISs are identified, to understand which components have the most impact. Based on the FMECA method. Maintenance policy decision step. The correct maintenance policy for each MCC is determined with a decision tree. Maintenance policies used are: Failure Based Maintenance, Design-Out Maintenance, Detective Based Maintenance, Condition Based Maintenance and Use Based Maintenance. Optimization of the preventive maintenance policy. For each component with its maintenance policy, the parameters of the policies should be optimized. Performance measurement and continuous improvement. Performance of the maintenance concept should be measured, to identify areas for improvement.
In short, this framework starts by setting objectives and requirements which the maintenance concept should meet. The plan is only about the MISs that are determined and its components with the highest impact. Those are not based on breakdown data, but identified with the FMECA-method. For those components, there is choice about 5 different maintenance policies which are optimized per component. After implementation, the performance is measures to continuously improve the developed concept.
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D 2. REVIEW FRAMEWORKS This section will compare the different frameworks and discuss the relevance of each framework for this case.
D 2.1. COMPARISON OF THE FRAMEWORKS The discussed framework of Gits defines 3 phases of the development of maintenance concepts. The first phase is to gather all known information for the development of a maintenance concept, the components of equipment and its failures; the preparation. During the second phase, maintenance policies per component are determined, maintenance tasks are formulated and a maintenance schedule is developed; the development. Lastly, the third phase evaluates the developed maintenance concept and verifies the set norms for the concept; the evaluation. Those 3 phases are also used in the MO method, developed by Heineken and roughly, those 3 phases can be seen in the steps of the other frameworks. These 3 phases are indicated as general phases (explained in section 5.1). However, the focus of the frameworks differs; where Gits focuses mostly on the development (step 1 till 6), other frameworks focus on the critical components for the maintenance concept (RCM) or improvement of it (Vanneste & Wassenhove). An overview is provided in Table 22. TABLE 22: PHASES IN EACH MAINTENANCE CONCEPT DEVELOPMENT METHOD
First phase Second phase Third phase Preparation Development Evaluation RCM Question 1 – 5 Question 6 and 7 MO (Heineken) Phase 1 Phase 2 Phase 3 Gits No concrete steps Step 1 – 6 Step 7 Vanneste & Wassenhove Step 1 and 2 Step 3 – 5 Step 6 – 8 Wayenbergh & Pintelon Step 1 – 3 Step 4 and 5 Step 6 The frameworks steps/questions of the methods and frameworks can be divided in the 3 phases. However, the deliverables after each phase en the method to reach those deliverables differ. Table 23 provides an overview of the deliverables after each step for each framework and Table 24 shows the methods used in each step. TABLE 23: DELIVERABLES OF THE MAINTENANCE CONCEPT DEVELOPMENT METHODS RCM
First phase - Preparation Equipment information and a finished FMECA.
MO (Heineken)
Breakdown and system information.
Gits
Technical analysis of the system.
Vanneste & Wassenhove
Location major downtime problems.
Wayenbergh & Pintelon
Requirements and objectives and the Most Critical Components of Most Important Systems.
Second phase - Development New maintenance concept with maintenance tasks. Based on 3 policies (run to failure, time based and condition based maintenance) Proposal for adjustments of the current maintenance concept. Based on 3 maintenance policies (run to failure, condition based, time based) and modifications. Maintenance concept with clustered maintenance tasks and grouped over time. Maintenance concept based on cost-benefit analysis of solutions of major problems. Maintenance concept with optimized parameters per policy. Based on 5 maintenance policies (failure based, design-out, detective based, condition based and use based maintenance).
Third phase - Evaluation
Implemented maintenance concept, once reviewed for costs, time and spare components. With measurable rejection criteria. Evaluated maintenance concept, for costs and demand. Implemented maintenance concept with monitored performance and if necessary back to step 1. Implemented maintenance concept with performance measurement and continuous improvement.
TABLE 24: METHOD PER PHASE FOR EACH MAINTENANCE CONCEPT DEVELOPMENT METHOD RCM
MO (Heineken)
First phase - Preparation Gather the supplier standards of each component. Identify functional failures, failure modes, consequences of failure and its criticality. Gather data from the system, current maintenance activities and its breakdown behavior.
Second phase - Development Based on the FMECA, formulate maintenance tasks to prevent or diminish consequences of failures. If a maintenance task is not sufficient, another way to prevent it from occurring is defined.
Third phase - Evaluation
Compare current maintenance with breakdowns. Evaluate existing concept and determine how to prevent breakdowns.
Review proposal for costs, time and spare components. Ask permission to adjust current documents and
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Gits
Gather data and analyze system failures, its consequences and the accessibility of components.
Vanneste & Wassenhove
Gather performance data and structure problems and their root cause.
Determine maintenance policy, based on decision tree (failure based, use based and condition based maintenance). Cluster maintenance tasks and smooth them over time. Generate solutions, analyze its effectiveness and efficiency and plan the actions, based on a costbenefit trade-off.
Wayenbergh & Pintelon
Set objectives and requirements. Identify Most Critical Components of the Most Important Systems, based on FMECA.
Determine maintenance policy, based on decision tree (failure based, design-out, detective based, condition based and use based maintenance). Optimize parameters for each policy.
implement adjustments. Evaluate maintenance tasks in terms of maintenance costs, maintenance demand and preventive maintenance. Implement the concept and monitor the actions and process data. If undesired, go back to the first phase. Implement the concept, measure its performance, identify areas for improvement.
D 2.2. RELEVANCE FOR HEINEKEN The framework of Gits is a methodology to develop maintenance concepts. The first phase is interesting for this case of Heineken, since data of breakdowns and its consequences is analyzed and this provides information of failure rates and failure time. Additionally, the hardware structure analysis is in line with the steps of Autonomous Maintenance, where accessibility of cleaning and lubrication tasks is determined and improved when needed. In the second phase, maintenance policies are assigned to components where the same three maintenance policies are used as in RCM, the maintenance methodology Heineken states to apply. The latter steps of phase 2, where maintenance tasks are clustered, harmonized and scheduled, are very interesting for Heineken, since the stopday is a fixed decision in the brewery and not directly based on maintenance plans. Those steps could provide a new view on the planning of maintenance activities. However, since this research only develops new maintenance concepts for a part of the production line, it may be difficult to change the maintenance schedule of the whole line. Although it can result in recommendations for further research on the other machines and alter the maintenance planning and stopdays. The last phase evaluates the developed maintenance concept and provides information about demand and costs. For Heineken, this is of interest to have more insight in the expected maintenance costs, expected spare components required and use of other resources and capacities. As opposed to Vanneste & Wassenhove and Wayenbergh & Pintelon, Gits does not mention to set goals and define restrictions, while the developed concept is evaluated in the last phase for norms and requirements. Regarding this research, the first 2 steps of the framework of Vanneste & Wassenhove are a good foundation for the development of a maintenance concept for Heineken. By using information of the current performance, maintenance can be used to prevent current breakdowns from occurring. Step 3, 4 and 5 are not clearly specified and therefore difficult to apply; no maintenance policies that should be used or a decision tree to determine the maintenance policy are provided. Additionally, since the goal of this research is to increase the OPI-Nona, costs are not the main criteria. It can occur that even if maintenance tasks are expensive, they are essential to increase the performance and therefore decisions should not only be based on a cost trade-off. The last three steps are interesting for Heineken, since currently they do not have a review procedure for their maintenance concepts. Those steps provide a guideline how to continuously improve maintenance concepts and prevent breakdowns. The framework of Wayenbergh & Pintelon starts with setting objectives and requirements for the maintenance concept. This is interesting for Heineken, since their goal is to increase the OPI-Nona for a determined amount of money. In the maintenance concept, not the whole system is taken into account, only the components with the highest impact of the most important systems are reviewed. The used components are based on FMECA; the methodology that was determined by Heineken as too time-consuming. This framework uses 5 maintenance policies, which provides a broad scope of possibilities for Heineken to identify the optimal one per component. The last step about continuous improvement is also interesting.
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APPENDIX E CONSTRUCTION REDESIGNED FRAMEWORK This appendix describes the construction of the redesign of the framework, per phase is explained which steps are removed, kept or changed and why, based on the steps shown in Figure 15.
E 1.
PHASE 1: PREPARATION MAINTENANCE CONCEPT DEVELOPMENT
In the first phase of the redesigned framework, several steps are added to the original MO framework. The following points describe per step why it is maintained or added to the redesigned framework.
Set objectives and restrictions. Wayenbergh & Pintelon specify the step to set requirements and objectives and Gits evaluates in the third phase the solution for a set norm although he does not specify a moment to set the norms. Heineken has specific performance targets like the OPI-Nona, a certain maintenance budget and sometimes direct reasons to improve a maintenance concept. Additionally, they have restrictions regarding the planned downtime moments and the capacity of maintenance experts. Therefore, objectives and restrictions will be determined in the preparation phase to be able to evaluate those restrictions in the last phase. Gather information technical system. The MO framework of Heineken describes to gather information about the technical system, like the Bill of Materials, the supplier, the age etc. This information is essential when evaluating its performance and determining a maintenance concept, thus this step is maintained. Gather current maintenance concept. Other frameworks from literature do not take current maintenance activities in account; they start without that knowledge. However, since the current maintenance concepts of Heineken influence the performance of systems and probably prevent breakdowns from occurring; only using breakdown data would give an incomplete picture of the problems of the system. Gather data breakdowns of the last year. This information is required to get insight in the performance of the technical system and the problem areas or critical components. Gather data breakdowns longer than 1 year ago. Except for RCM, which can develop maintenance concepts for new systems without any history, information of the system and its breakdowns is gathered by all other frameworks. However, they do not have a predetermined time limit like the one year of the MO framework. Since more historical data can provide more information and a broader base to estimate a lifetime of a component, this restriction is not taken into account and all available information from SAP will be gathered. In the first step ‘Gather equipment information’, it is important to pay special attention to modifications or other activities with large impact on the system, to secure the value of older information. Verify gathered data. Currently, it is not fully certain that data registered is corresponding with the real activities of equipment. Registration is not always correctly; this should be verified before analyses based on the data are executed. Gather data breakdowns similar technical systems. Heineken uses similar machines on other production lines and in other breweries. Breakdown data of those technical systems can provide extra insight in the breakdown behaviour and life time of components. Therefore, this step is added to the framework. Gather data spare components. None of the reviewed frameworks specifically mentions the spare components in stock and the consumption of them. However, this data will provide further insight in the breakdowns. Additionally, the repair time of a component depends on the stock of spare components; if a spare is not in stock and should be ordered at the supplier in case of a breakdown, the repairtime is longer. Determine Maintenance Significant Components. In this step is determined which components of a technical system will be taken into account in the development of the maintenance concept and which 84
not. Section 6.2 explains the shortcomings of the current method of Heineken and section 6.3 describes the redesign.
E 2.
PHASE 2: DEVELOPMENT MAINTENANCE CONCEPT
Phase 2 of the redesigned framework is changed quite a lot compared to the second phase of the MO framework. The following points explain per step why it is changed, added, removed or maintained.
Color breakdowns in ISO-metric. This step of the original MO framework is maintained. By coloring the breakdowns in an ISO-metric with the whole team, visual overview is created to use as input for the discussion. It gives the whole team more insight to the problem area and the impact of the problems. Since the team-members do not know all breakdowns of the system that occur out of their working shifts, this step shows them the impact of all breakdowns, the problem areas of the breakdowns and provides more knowledge of the exact location of failures. Therefore, while it is a time-consuming step, it is of interest for the process to make the problem understandable and get all team-members involved. Colour maintenance activities in machines ISO-metric. This step is time-consuming while the outcome is not essential for the development of a new maintenance concept; it only gives an overview of current activities. Therefore, it is decided to remove the step from the framework. Determine relevant maintenance policies. The MO framework uses four maintenance policies, while other frameworks reviewed define more and other maintenance policies. APPENDIX G will provide a list of references of additional maintenance policies shown in the overview in section 7.2. The newly added maintenance policies provide new opportunities that could be profitable for Heineken to apply. Therefore, the step ‘Determine relevant maintenance policies’ is added. Determine maintenance policy and tasks per MSC. The step in which the maintenance concept is determined, is splitt in three steps in the redesigned framework. A new method of determining the maintenance concept is used. The shortcomings of the method of the MO framework and the causes of the redesign are discussed in the Chapters 8, 9 and 10. o Determine possible maintenance policies. Shortcomings of the current method of determining which maintenance policy should be applied at which component are discussed in section 8.2.4. A redesign of the method is discussed in section 8.3. o Determine optimal parameter values. Wayenbergh & Pintelon specifically appoint that optimal parameters of each component policy should be determined; to get the best insight in an optimal maintenance concept. Currently, values are based on experience of maintenance personnel and limited by the planned maintenance moments and costs related to different policy parameters are not compared. This step is added to find the maintenance policy parameter corresponding to the lowest costs. o Determine maintenance concept. With the research per MSC of the previous new steps, it will be decided which maintenance policy will be applied at which MSC, based on the costs of executing that maintenance policy. This cost aspect was not taken into account in the MO framework, while it is an important variable. Determine required spare components. This step is moved from the third to the second phase. The current spares in stock are a result of developed maintenance concept; everything required to execute the maintenance concept is added in stock. However, since spare components in stock influence repair time, stock value and material costs, it is important to take this into account while determining the new concept. Cluster/harmonize activities. Gits (1992) allocates much attention to the planning of the maintenance activities, by clustering and harmonizing; aspects that are scarcely mentioned by the other frameworks and MO. For Heineken this could be very interesting, since the planned downtime is
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currently exceeded (Table 20) and moments of planned downtime are not determined based on accurate calculations and do not depend on maintenance activities. Group activities. Currently, all inspection cards need to be executed in the same moment of time and the packer-specialist has once in the 3 months a lot of work at the packer, the other stopdays there are no planned maintenance tasks for the packer, mainly cleaning activities and maintenance orders are executed. It is interesting to investigate what maintenance schedule would be optimal for the packers, regarding required resources and planned downtime.
E 3.
PHASE 3: EVALUATION DEVELOPED MAINTENANCE CONCEPT
MO evaluates the developed maintenance concept for costs, time and required spare components. Next, adjustments to the current concept are made and approval of the Rayon technician is asked. Then, the new concept can be implemented and lastly it is checked if the concept really is implemented in the systems. Literature introduces other aspects, of which the following is added to the framework:
Evaluate costs of determined tasks (€ PM < € breakdown). In the original MO framework, a maintenance task was only executed if the costs of the planned maintenance activities are less than the expected costs of a breakdown. However, in order to reach the OPI-Nona target, it could be required to reduce the expected unplanned downtime by investing in planned maintenance. Therefore, this evaluation step is removed from the framework. Evaluate required time and spare components. The step regarding required spare components is moved to the second phase and already discussed. The evaluation of time (and resources) is included in the step ‘Group activities’; the last step of the second phase. This step is thus removed from the third phase. Evaluate objectives and restrictions. In the first phase, objectives and restrictions are set. Those should be evaluated for the proposed maintenance concept, like the set OPI-Nona goal, the cost budget, planned downtime and maintenance department capacities. Ask permission for adjustments. At Heineken, there are specific procedures for adjustments of the maintenance concept. Those steps are included in the redesigned framework, to be sure that the formal procedure is followed. The rayon management should approve the new maintenance concept. Adjust documents maintenance concept. Since the maintenance concept is saved in several documents, besides the registration in SAP, this step is added to not forget one of those documents. Else, two maintenance concepts will mix up and not be executed correctly. Check implementation in all documents. Lastly, this step is added to check if the maintenance concept is correctly implemented and functioning. After completion of this step, the maintenance improvement project team is finished with their task and can be dismissed.
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APPENDIX F EXPLANATION CRITICALITY ANALYSIS Criticality analysis is known by Heineken as FEMCA (Failure Mode, Effects, and Criticality Analysis), an extensive method to investigate the importance of each possible failure mode of each component. This FMECA is the starting point of the development of a maintenance concept according the Reliability Centered Maintenance framework. Heineken states to use the RCM methodology; however, since the execution of an FMECA is highly time-consuming Heineken developed an own methodology. They still use the Criticality Analysis of this method, to determine if it is worth to put effort in maintenance activities for a specific component. In general, a criticality analysis calculates a risk number for a component i regarding a risk category j. This risk number can be calculated by: (F.1) With effect defined as the effect of the failure of that component in a specific risk category and probability defined as the probability that the effect of the failure of that component in a specific risk category will occur. This number provides the following information: { If at least one category gives a significant result, the component is seen as critical part. If none of the risk categories is significant, the component is seen as not critical. Figure 45 provides a table with input for this criticality analysis, with the parameters approved for the Packaging department of Heineken Zoeterwoude (2007). Heineken uses the risk categories: Breakdown, Safety, Environment, Repair costs and Quality. The probability is measured on an exponential 5-point scale (1, 2, 4, 8, 16) with higher numbers for a higher probability. Multiplication of the effect-number with the probabilitynumber gives the risk number for a specific risk category of a component. If this result is higher than the specified risk limit, the combination in the matrix is colored red and the component is seen as a critical part. Components with all risk numbers below its limit are determine to be non-critical. In Figure 17 of section 8.1, the table shown in Figure 45 is summarized in one scheme that directly provides insight in the criticality of a component.
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Criticality Matrix Packaging Zoeterw oude Accepted May 24, 2007 by HNS TPM PM stuurgroep Dow ntim e Risk = Probability x Effect
EFFECT
> 5Y € 0 tot €1.000,- (breakdow n <1h) €1.000,- tot €10.000,- (breakdow n >1h<10h) €10.000,- tot € 50.000,- (breakdow n >10h <2 days) €50.000,- tot €200.000,- (breakdow n >2days < 1 w eek) > €200.000,- (breakdow n > 1 w eek) Risk lim it
Risk 2 6 18 54 162 45
1 2 6 18 54 162
Probability 1Y tot 5Y3M tot 1Y1M tot 3M0 tot 1M 2 4 8 16 4 8 16 32 12 24 48 96 36 72 144 288 108 216 432 864 324 648 1.296 2.592
Safety Risk = Probability x Effect
EFFECT
> 5Y Risk 2 6 18 54 162 60
No effect Visit First Aid Accident w ithout absence Accident w ith absence Fatal accident Acceptable risk level
1 2 6 18 54 162
Probability 1Y tot 5Y3M tot 1Y1M tot 3M0 tot 1M 2 4 8 16 4 8 16 32 12 24 48 96 36 72 144 288 108 216 432 864 324 648 1.296 2.592
Environm ent Risk = Probability x Effect 1 1 3 9 27
Probability 1Y tot 5Y3M tot 1Y1M tot 3M0 tot 1M 2 4 8 16 2 4 8 16 6 12 24 48 18 36 72 144 54 108 216 432
1 1 2 4 8 16
Probability 1Y tot 5Y3M tot 1Y1M tot 3M0 tot 1M 2 4 8 16 2 4 8 16 4 8 16 32 8 16 32 64 16 32 64 128 32 64 128 256
1 1 4 16 64
Probability 1Y tot 5Y3M tot 1Y1M tot 3M0 tot 1M 2 4 8 16 2 4 8 16 8 16 32 64 32 64 128 256 128 256 512 1.024
EFFECT
> 5Y Risk 1 3 9 27 25
No effect Leakage / spill non toxic product Leakage / spill toxic product Leakage / spill toxic product beyond acceptable level Acceptable risk level Repair cost Risk = Probability x Effect
EFFECT
> 5Y Risk 1 2 4 8 16 30
€ 0 tot €200,€200,- tot €1.000,€1.000,- tot € 5.000,€5.000,- tot €20.000,> €20.000,Acceptable risk level Quality Risk = Probability x Effect
EFFECT
> 5Y Risk 1 4 16 64 40
No impact Acceptable (product in spec) Frozen product (product out of spec) Recall / consumer safety Acceptable risk level
FIGURE 45: CRITICALITY MATRIX PACKAGING DEPARTMENT HEINEKEN ZOETERWOUDE
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APPENDIX G REFERENCES MAINTENANCE POLICIES Maintenance policy
Explanation
Minimal repair
Component is restored to the condition it had before the failure occurred, to start production as soon as possible. Also called ‘bad as old’ or imperfect repair. Failed component is repaired, to an ‘as good as new’ component. The component is replaced by a new or repaired one, after failure. At failure, the component is repaired. If the repair takes longer than a predetermined time, the component is replaced by a new one. A component is replaced when the failure rate of a component reaches a specified level or when reliability of a component is below a specified level. Other failures are fixed through minimal repair. At failure, a trade-off is made between expected repair costs and replacement. If repair costs are below a specified level, the component is repaired; otherwise it will be replaced. A component is replaced if its number of failures reaches a predetermined number. Failures before are fixed by minimal repair. A component is replaced if it fails after a predetermined time. Failures before that time are fixed through minimal repair. Preventive maintenance is applied when the component reaches a specified age. Preventive maintenance following unequal time intervals, based on the perspective that systems need more frequent maintenance if they get older. A periodic preventive maintenance policy; a component is preventively maintained at fixed times, independent of breakdown and repair history of the component. The component is continuously monitored or inspected. If the component reached a predefined state, it will be maintained.
Perfect repair Corrective replacement Repair time limit policy Failure limit policy
Repair cost limit policy
Repair number counting policy Reference time policy Age dependent policy Sequential preventive maintenance policy Block policy
Continuous monitoring policy (CBM and predictive maintenance) Periodic inspection policy (CBM and predictive maintenance) Sequential inspection policy (CBM and predictive maintenance)
After a fixed amount of time, the component will be inspected and it is determined if the components need maintenance or not. The component is periodically inspected, however not after a fixed time. At the moment of inspection, it is determined if the component needs replacement or not. If no replacement is required, it is decided when the next inspection should be executed.
Reference (Lie & Chun, 1986) (Barlow & Proschan, 1975) (Lie & Chun, 1986) Overview of several types given by Wang (2002) Overview of several types given by Wang (2002) Overview of several types given by Wang (2002) Overview of several types given by Wang (2002) Overview of several types given by Wang (2002) Overview of several types given by Wang (2002) Overview of several types given by Wang (2002) Overview of several types given by Wang (2002) (Grall, Bérenguer &Dieulle, 2002) (Grall, Bérenguer & Dieulle, 2002) (Grall, Bérenguer & Dieulle, 2002)
Barlow, R. E., & Proschan, F. (1975). Statistical Theory of Reliability and Life Testing. New York: Holt, Rinehart & Winston. Grall, A., Bérenguer, C., & Dieulle, L. (2002). A condition-based maintenance policy for stochastically deteriorating systems. Reliability Engineering & System Safety , 76 (2), 167-180. Lie, C. H., & Chun, Y. H. (1986). An algorithm for preventive maintenance policies. IEEE Transactions on Reliability , 71-75. Wang, H. (2002). A survey of maintenance policies of deteriorating systems . European Journal of Operational Research , 469-489.
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APPENDIX H LITERATURE REVIEW MAINTENANCE POLICY DECISION TREE This appendix provides an extensive literature review as input for the redesign of the maintenance policy decision tree as currently used by Heineken. Firstly, characteristics of the several maintenance policy categories are provided. The main points are summarized per maintenance policy in Table 25. This review is used as input for section 8.2 and 8.3. It is important to mention that in this appendix predictive maintenance is included in the category condition based maintenance (CBM). Since, as explained in section 7.1, Heineken sees predictive maintenance as a different category, while literature mainly sees predictive maintenance as part of condition based maintenance. Additionally, it is stated in section 8.2.1 that modification is seen as separate option and is not taken into account in the maintenance policy decision of Heineken. However, in most decision tools that are described in this chapter, a modification is included; probably in case the current optimal policy does not perform as expected, not because it is always the best option.
H 1. MAINTENANCE POLICY DECISION TOOLS H 1.1. DECISION MAKING GRID OF LABIB Aslam-Zainudeen & Labib (2011) describe the application of the Decision Making Grid (DMG) as developed by Labib (1996). The decision of a maintenance policy depends on the frequency of the failure and the downtime per failure; the interesting parameters for Heineken regarding this research, since it aims to increase the availability. This DMG is shown in Figure 46, where based on the downtime and frequency of a failure, a maintenance policy FIGURE 46: DECISION MAKING GRID, BASED ON LABIB (1996) category is classified to that component. The maintenance policies from this figure correspond with the explanation in section 7.2 only SLU is a new policy. Skill Level Upgrade means to upgrade the skill level of operators and maintenance personnel to solve this type of failure.
H 1.2. MAINTENANCE POLICY DECISION TREE WAYENBERGH & PINTELON (2002) Wayenbergh & PIntelon (2002) developed a maintenance policy tree that per component checks firstly if a specific maintenance policy is technical feasible and secondly, if the economic aspects are achievable. This maintenance tree is shown in Figure 47. A question including ‘T?’ means if it is technical feasible; a question including ‘E?’ asks to make a costbenefit trade-off. Answering those questions, it will bring each component to the most interesting maintenance FIGURE 47: MAINTENANCE POLICY DECISION TREE, BASED ON WAYENBERGH & policy category for each. PINTELON (2002)
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H 1.3. MAINTENANCE POLICY DECISION TREE WAYENBERGH & PINTELON (2004) In another research of Wayenbergh & Pintelon (2004), the maintenance policy decision diagram as shown in Figure 48 is developed. They broadly use the same maintenance policies and categories as in this research, however the terms used are different. Translated to this research: FBM = Corrective Maintenance (CM), DBM = Condition Based Maintenance (CBM â&#x20AC;&#x201C; Inspections), USB = Time Based Maintenance (TBM â&#x20AC;&#x201C; Production Time), DOM = Modification and CBM = CBM. Since outsourcing is not taken into account, as mentioned in the first chapter, not all boxes of this diagram are of value. In this scheme, priority determines if corrective maintenance is applied or not. If priority is high, firstly is checked of a modification is possible, then Time Based Maintenance and lastly Condition Based Maintenance. Before determining the policy, the advantages/disadvantages are considered and change to another strategy is possible.
FIGURE 48: MAINTENANCE POLICY DECISION DIAGRAM, WAYENBERGH & PINTELON (2004)
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H 1.4. MAINTENANCE DECISION LOGIC RAUSAND Rausand (1998) developed a small and simple decision tree and provided criteria for components to determine what maintenance category is useful to apply. Firstly, all components that can be maintained by Condition Based Maintenance are filtered. Secondly, it is asked if the ageing parameter of the component is larger than a predetermined X, to determine for which components Time-Based Maintenance is a relevant option. If both answers are no, the decision is made if a component will be maintained according run to failure, since I is obvious if a component fails. However, if the failure is hidden, it is decided to still apply CBM.
Does a failure alerting measurable indicator exist?
Condition Based Maintenance
Yes
No
Is ageing parameter > X?
Yes
Is overhaul possible?
Yes No
No
Is the function hidden?
Yes
Time Based Maintenance repair Time Based Maintenance replacement
Condition Based Maintenance
No
Corrective Maintenance
FIGURE 49: MAINTENANCE DESICION LOCIG DIAGRAM, RAUSAND (1998)
H 1.5. MAINTENANCE POLICY DETERMINATION TSANG Tsang (2002) did not make a maintenance decision tree or flow diagram; however, he explained what type of maintenance should be applied for which characteristics of a component. Corrective Maintenance. This type of maintenance should be applied at components with failure that has inconsequent impact on the performance of the system. Or it can be applied at components where the investment in preventive measures is higher than the expected benefits from avoiding the failures from occurring, like a higher availability of improved reliability. Time Based Maintenance. A characteristic of TBM is that the component is maintained, regardless of its condition. Tsang (2002) warns suppliers’ recommendations are mostly formulated with limited experience or knowledge about use conditions and are therefore seldom optimal. He states that factual information is required (like time-to-failure distributions, costs of maintenance and consequences of failure) to optimize TBM intervals. Condition Based Maintenance. CBM prevents ‘over-maintaining’ of a component; maintenance is only executed when failure is judged to be impending. Modification. Tsang states that such a design improvement can be executed if it achieves one of the following objectives: “improve reliability, enhance maintainability, minimize maintenance resource requirements and eliminate the need of routine servicing” (Tsang, 2002).
H 1.6. MAINTENANCE POLICY DECISION DIAGRAM OF STORK MAINTENANCE MANAGEMENT One of the extern advice companies Heineken consulted for their vision on maintenance is ‘Stork Maintenance Management’. They provided a diagram (shown in Figure 50) to determine what maintenance policy category to apply at what type of component. It is provided in Figure X in Dutch. A ‘TAO Taak’ means Condition Based Maintenance, a ‘GAO Taak’ is Time Based Maintenance and SAO means corrective maintenance.
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FIGURE 50: MAINTENANCE POLICY DECISION DIAGRAM OF THE STORK MAINTENANCE MANAGEMENT METHOD (STORK TECHNICAL SERVICES)
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TABLE 25: OVERVIEW MAINTENANCE POLICY DECISIONS FROM LITERATURE
Corrective maintenance (CM) Not critical with apparent failure. Or critical, no increasing failure rate, no deterioration detectable and acceptable repair time. Low frequency and low downtime. Not critical. Or technical and economical best.
Time Based Maintenance (TBM) Critical, increasing failure rate, no deterioration detectable. Or deterioration detectable and €TBM < €CBM. Medium frequency or medium downtime Not CM, Mod or CBM and condition predictable and economic interesting.
Wayenbergh & Pintelon (2004)
No priority
Priority. Increasing failure probability, slight increase, economic
Rausand (1998)
Because other tasks are not possible or not interesting from an economic point of view. Inconsequent failure of a component or if investment in preventive maintenance is higher than expected benefits.
Identifiable age with rapid deterioration (proved by large portion components),
If none of the other policies is applied. Possibly combination with other required task to prevent failure.
Not CBM. TBM technical and economical interesting
Maintenance policy decision tree Heineken
Labib (1996) Wayenbergh & Pintelon (2002)
Tsang (2002)
RCM by Stork Maintenance Management
Factual information about a component is required, like time-tofail distributions and expected costs.
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Condition Based Maintenance (CBM) AM: Not critical with hidden failure. Or critical, deterioration detectable and €CBM < €TBM.
Low frequency and high downtime. Not CM or Mod. CBM if failure is hidden and detectable. Predictive maintenance is condition measurable and economic interesting. Priority Condition detectable/measurable? CBM economic? Possible to detect reduced failure resistance, possible to define failure condition, age interval potential failure and failure. Only when failure is judged to be impending.
Detectable when failure will occur and worth to inspect/measure. Or test to find hidden failures interesting.
Modification (MOD) Critical, no increasing failure rate, no deterioration detectable, time to repair not acceptable.
High frequency and high downtime. Not CM and redesign technical and economic possible.
Priority Can be eliminated? Modification possible? Mod economic? -
If it improves reliability, enhances maintainability, minimizes maintenance resource requirements or eliminates the need of routine servicing If failure can be dangerous for safety, environment, quality. If technical possible.
APPENDIX I SCHEMATIC LAY-OUT PACKERS LINE 7 Figure 51 is a schematic overview of the lay-out of the packer 72, developed by Heineken. Packer 71 is a similar system, but its lay-out is mirrored. The numbers of this overview are linked to the assembly name, provided on the next page. Table 26 provides a list of the assemblies shown in Figure 51. In the Bill of Material that will be developed according the redesigned framework, these assemblies are further divided in sub-assemblies.
FIGURE 51: SCHEMATIC LAY-OUT PACKER 7
95
TABLE 26: ASSEMBLIES ISO-METRIC DRAWING
1 Aandrijving flessenaanvoerbaan
45 Stuur ventiel
2 Aandrijving flesseninvoertafel
46 Lengte-instelling doos
3 Aandrijving trekstang
47 Breedte-instelling doos
4 Aandrijving flessendoorvoermat
48 Stuur ventiel
5 Aandrijving grid
49 Trekstang instelling
6 Aandrijving dozenuitloop
50 Bedieningskast
7 Aandrijving indexer
51 Noodstop voorzijde
8 Flessenlaantjes
52 Noodstop achterzijde
9 Kast servo's
53 Benaderingsschakelaar fles laan 1
10 Ventilator kast servo's
54 Benaderingsschakelaar fles laan 2
11 Flesgeleiders
55 Benaderingsschakelaar fles laan 3
12 Schakelkast (bordes
56 Benaderingsschakelaar fles laan 4
13 Geleideblok airbag
57 Stuur ventiel
14 Alarmlamp
58 Stuur ventiel
15 Spacers
60 Veiligheidsschakelaar deur voor
16 Leeg-detectie smeertoestel
61 Veiligheidsschakelaar deur achter
17 Luchtcylinder anti-kantel mechanisme
62 Veiligheidsschakelaar deur links
18 Ketting aandrijving flessendoorvoermat
63 Veiligheidsschakelaar deur rechts
20 Baanregeling schakelaar
64 Ketting grid - binnenkant
21 Airbag
65 Schokdemper laadplateau
26 Baanregeling schakelaar
66 Schokdemper laadplateau
27 Hoogteverstelling bovenste flessenstop
67 Schokdemper laadplateau
28 Benaderingsschakelaar trekstang
68 Schokdemper laadplateau
29 Luchtcylinder onderste flessenstop
69 Lagers laadplateau
30 Benaderingsschakelaar valplaat
70 Automatisch smeertoestel (vet)
31 Grid
71 Automatisch smeertoestel (olie)
32 Luchtcylinder valplaat
72 Lagers laadplateau
33 Luchtcylinder valplaat (als 32)
73 Ketting lengte-instelling doos
34 Benaderingsschakelaar grid
74 Schakelaar dozenketting
35 Ketting grid - buitenkant
75 Storingsdisplay
36 Luchtcylinder kettingspanner
76 Drukschakelaar luchtnet
37 Luchtcylinder dozenindexer
77 Tandriem trekstang
38 Kettingwiel dozendoorvoerketting
85 Gridvinger
39 Fotocel dozentoevoer
87 Trekstang
40 Geleiding dozendoorvoerketting
91 Dozengeleiding dozenuitvoer
41 Stuur ventiel
92 Valplaat
42 Stuur ventiel
93 Begeleidingsrol indexer
43 Meenemer
95 Flesgeleiding flesseninvoer
44 Dozendoorvoerketting
96
APPENDIX J ADJUSTMENTS BREAKDOWN REGISTRATION As explained in section 11.5, the data gathered by the system monitoring system MES Verpakken is not reliable. Therefore, the changes that are made in the downtime registration program are mentioned below.
The notification ‘Dozen toevoer’ was registered as unplanned downtime; however, this was lack of input. It this photocell did not see a box for 3 seconds, it was registered as a minor stop or breakdown time, while the machine could not produce through a lack of boxes. The notification ‘Alarm onbekend’ was a rest-notification for all unplanned downtime without a specified cause. Several extra downtime notifications are developed and added to the registration, to better define what the cause is of a failure. Like the notifications ‘Flessen 3 sec. niet voor trekstang’, ‘Setup Sleutelschakelaar’ and ‘Servo’s niet home’. If the production line needs to be emptied because of an order change with different labels, boxes or bottles, firstly packer 71 is emptied. Then, packer 72 is emptied which takes about 20 minutes. Those 20 minutes are registered as unplanned downtime (breakdown time) for packer 71, since it is only possible to start a production stop for an order change in the program for both packers together. Therefore, an extra registration button is added where operators can choose the option ‘Emptying’ per machine, which will be registered as production stop. There were differences in the registration of packer 71 and 72, i.e. different names for unplanned downtime categories and the time the system waited before registering unplanned downtime. Together with the project team is determined what the best names are for unplanned downtime causes and when they have to be registered. Then, the registration of the packers is made equal. The error ‘Servo’s niet home’ occurs often; every time one of the four servo motors is not working properly. It is decided to split this error in 4 different errors; one per motor: ‘Servo flessenbaan niet home’, ‘Servo grid niet home’, ‘Servo trekstang niet home’ and ‘Servo dozendoorvoer niet home’, to adress the cause of the unplanned downtime more specific.
With those improvements, the registered unplanned downtime of the packers will be more reliable and provide an overview of the actual problems and performance of the system.
97
APPENDIX K MAINTENANCE SIGNIFICANT COMPONENTS (BOM) Table 27 is the list of all Maintenance Significant Components (MSCs) and will be implemented in SAP as the Bill of Materials (BOM). This list is developed during the execution of the redesigned framework by the project team. If the Hartness code is not given, the component is replaced by a component of an other supplier or constructed by the maintenance department of Heineken itself. If there exists no component number of SAP, the component is not registered as spare component in the general stock. A â&#x20AC;&#x2DC;PDâ&#x20AC;&#x2122; code means that a SAP number is requested, although it takes time to establish it. TABLE 27: LIST OF ALL MAINTENANCE SIGNIFICANT COMPONENTS
Packer 71&72 1 Dozentransport 1 Dozeninvoer 1 Draagrol 2 Indexer 1 Kettingspanner 1 Cylinder kettingspanner 2 Gaffel 3 Bus 4 Smoorventiel 5 Slijtplaat 6 Reactie arm 7 Flenslager 8 Pen, M12 X 50 9 Veer ring 2 Dozenwip 1 Ketting 2 Kettingwielen 3 Curveschijf 4 Curverol 3 Flenslager 4 Begeleidingsrol 5 Kraagbus 3 Dozendoorvoerketting 1 Ketting (2x) 1 Kettingwielen 2 Meenemers 1 Achterste meenemer 2 Voorste meenemer 3 Vulplaat 4 Stalen meenemer 3 Flenslager 4 Flenslager 5 Kettinggeleidingen 1 Verbindingsstuk 2 Verlenging geleiding top 3 Geleiding top 4 Geleiding bottom 5 Verlenging geleiding bottom 4 Aandrijving 1 Servo motor 1 Reductor - RH 2 Koppeling - dempingsster 2 Aandrijfas dozendoorvoerketting 3 Klembus 4 Duplex ketting 5 Doos afsteller 1 Lengteverstelling doos 2 Breedteverstelling zijgeleiding 1 Ketting 2 Tandwielen 3 Knop 3 Dekplaat cylinder
Amount in 1 packer
Component code Hartness (supplier)
1
D-1095
2 2 2 2 4 1 6 1 2
N-812 N-811 N-815 N-75C 28-300-403 28-350-32 D-1418 F-1077 H-547
70045752 70045864 70181837 70034182
2 4 1 1 2 1 2
28-300-488 D-864 D-1418 28-300-602 D-1508
PD 70034172 70044109 PD 70034365
2 4
D-1109 D-858
70118385 PD
16 16 16 32 2 2
28-350-07 28-300-12 28-300-249 Kasteel D-1418 D-1420
70034187 70034188 70034189 PD 70044125 70044069
4 1 2 2 1
11-302-14 28-300-440 LH 11-302-12 LH 28-300-539 LH 28-300-543 LH
PD PD PD PD PD
1 1 1 1 1 2
D-1244 D-848 28-750-01 28-350-195 D-1436 D-1126
70034430 70160660 70034193 70045019 70044793
28-300-622 N-815
70181837
Component number SAP
70034163 PD PD
1 1 2 1 1
98
4 Borgmoer RH 5 Borgmoer LH 6 Afstelring 7 BEARING, CASE, ADJ 6 Dozenuitvoer 1 Uitvoerrollen 2 Centreerpennen 2 Flessentransport 1 Flesseninvoer 1 Flesseninvoertafel 1 Bochtenketting 2 Bochtenkettingwiel 3 Meeloopwiel 4 Kunststof flessenmat 5 Kettingwiel flessenmat 6 Ketting geleider 7 Kettingwielen 8 Aandrijving flessenketting 9 Aandrijving flessenmat 10 Overgangsplaat flessenmat 11 Flenslagers 12 Kettinggeleider 13 Servo motor 1 Reductor 14 Kettingwielen 15 Ketting 2 Flessenlaantjes 1 Flesgeleidingen 2 Flesgeleidingen 3 Inloopvinnetjes 4 Spacers 5 Klem spacers 2 Onderste flessenstop 1 Montagebeugel 2 Cylinder 3 Gaffel 4 Montageplaat 3 Anti-kantel mechanisme 1 Gaffel 2 Cylinder 3 Smoorring 4 Gaffel 5 Vork 6 Kogelgewricht 7 Gaffelpen, M12 x 30MM 3 Inpaktafel 1 Lift systeem 1 Servo motor 1 Reductor 2 Koppeling - sterretje 2 Ketting 3 Kettingwielen 4 Taperlock 5 Veren kettingspanner 6 Geleideblokken 7 Aandrijfas lift 8 Flenslager 9 Klembus 10 PLATE, MOUNT, SERVO 2 Demptafel 1 Schokdemper 2 Geleideblok 3 Cover plaat plateau 4 Demperplaat 3 Lift stel 1 Klem 4 Trekstang 1 Aandrijving
3 3 3 5
11-300-24 11-300-25 28-300-86 28-300-26
70034183 70034184
24 8
D-320 F-362
70034169
1 4 1 1 40 1 2 1 1 1 12 3 1 1 2 1
D-1404 D-3115 D-3116 D-29
70034190
70044930 70044926 70044889 70044983 70044961 70034288 70044889
D-1721N D-1720N 28-450-171 D-1420 30-705-26 D-1244 D-1642A D-1464 D-13
PD 70044069 PD 70034430 70160660 PD 70044787
5 5 5 12 7
28-450-182 28-450-183
70034243 70034244
H-690
70034177
1 1 1 1
28-400-303 LH N-812 N-811 N-815
70045752 70045864 70181837
1 1 1 1 1 1 1
28-450-107 N-812 N-336 N-816 N-865 N-866 F-1096
1 1 1 2 4 4 8 4 1 8 4 4
D-1317 28-750-01 28-200-326 D-988 28-300-518 H-544 28-200-39 28-200-247 D-1419 D-1427 28-200-225
4 4 2 2
N-655 28-200-166 28-250-84 28-200-218
70034181 70034186 PD PD
2 1
H-802 28-400-422
70034177 70034245
99
70045752 70034182 70046323 70046323 70045883
70034159 70034161 70034193 70034212 70034780 PD 70034248
70034164 70045005 PD
1 Servomotor 1 Reductor 2 Koppeling 2 Tandriem 3 Tandriemwielen 4 Lagerblok airbags 5 As meeloopwiel 6 Aandrijfas trekstang 7 Aandrijfas trekstang 8 Aandrijfas trekstang 9 Koppeling aandrijfas trekstang 10 Liniear lager 11 Keer ring 12 Borging 2 Inlooplaantjes 1 Airbag 2 Airbag 3 Airbag 3 Bevestigingsplaat 5 Valplaat 1 Flessenstop 1 Onderste flessenstop 2 Stop blok 3 Stopper 4 Bevestigingsbout 2 Luchtcylinder 3 Demper 4 Slijtstrip 1 Slijtstrip voorkant 2 Bevestiging slijtstrip 3 Slijtstrip achterkant 5 Vulring 6 Veer 7 Fitwerk 1 Nippen 2 Stop H-655 3 Stop H-657 8 Schroefdraad koppeling 9 Demper 10 Flappenspreider 11 Overgangsplaat 6 Grid 1 Luchtcylinder 2 Gridvinger 3 Gridveertje 4 Grid pen 5 Vorkplaat 6 Schroefdop 7 Kam 8 Conus kegel 9 Bevestigingsring 1 O-ring 2 D-ring 10 Bus 11 Bus 12 Blokgeleiding 13 Fitwerk 1 Snelkoppeling H-542 2 Snelkoppeling H-179 14 WASHER, FLAT, 1/2 15 WASHER, FLAT, 5/16 16 BUSHING, TRANS BAR 17 BUSHING, TRANS BAR 18 Overgangsplaat 1 Bevestigingsplaat 2 Bevestigingsplaat 3 Sleeve 4 Bus
1 1 1 2 4 2 2 1 1 1 2 4 4 1
D-1244 D-880 D-1919 D-982 D-1089P 28-450-114 28-450-131 28-450-343 28-450-341 28-450-342 D-2173 D-1598 D-1623 H-562
70034430 70121401 70034193 70034174 PD PD Heineken Heineken Heineken Heineken PD PD PD PD
1 3 1 2
8-424-FYRHB 8-424-FYXB 8-424-FYRLB 28-450-80
70034216 70034217 70034218 PD
1 4 1 4 1 2 1 2 2 2 2 2 1 1 2 2 4 2 1 102 38 4 38 38 5 38 15 13 10 5 4 1 1 10 10 3 1 5 5 5 5
100
N-814 28-650-37
70034208 70034254 70034209 70034210 70045752 70034252
28-650-43 28-650-74 23-302-95 H-532
70034192 70034250 70034251 70034253 70034352
H-297 H-655 H-657 H-45 28-650-24S
70034256 70034259 70034258 70034257 70034267
28-600-139
70034255
F-1126
70034238
4-609-12 4-609-03
70034262 70034263 70034266
28-400-502
F-75 F-78 D-1688 D-1689 8-613-13 8-613-17 8-609-240
70085027 70085028 70034268 70034260 70034236 70034237 70034261 70034265 70034269
5 Montageplaat 6 Verbindingsstrip plaat 7 Verzorgingsunit schakelventielen 1 Ventielen 1 Magneetventiel 2 Magneetventiel 3 Magneetventiel 4 Magneetventiel 5 Reduceerventiel 6 Filter, vacuum 8 Algemeen 1 Servo benodigdheden 1 Servo kabel C-1288 2 Servo kabel C-1289 2 Interface printkaart 3 Schakelaar 1 micro schakelaar 18pa1 2 micro schakelaar 201cs1 4 Fotocellen 1 Fotocel WL36-B230 2 Fotocel PRK 97/4L 5 Overkapping 1 Gasveer
1 1
1 1 1 1 1 1
28-600-245
70034264 70034235
8-425-127 N-385A
70034179 70034180 70034230 70034232 70034239 70327140
4 4 1
70034153 70034154 70034156
1 1
70034175 70034176
1 1
70041271 70041278
7
101
D-975
70034234
APPENDIX L ANSWERS MAINTENANCE POLICY POSSIBILITIES TREE In Table 28, the list of MSCs is provided with answers to the questions of the maintenance policy possibilities tree from Figure 37. The answer ‘yes’ is indicated with a Y, ‘no’ with the N. An ‘–‘ indicates that the question is not asked any more, since the component came already to its final ‘maintenance policy possibilities’-box in the decision tree. TABLE 28: ANSWERS MAINTENANCE POLICY POSSIBILITIES TREE PACKER 7 FOR ALL MSCS
Packer 71&72
Increasing failure rate?
Deterioration detectable?
Condition measurable?
Planned replacement time < 6 hr?
N
-
-
Y
Y Y Y Y Y Y Y Y Y
Y Y N N Y N Y N N
Y N N Y -
Y Y Y Y Y Y Y Y Y
Y Y Y Y Y Y Y
Y Y Y Y Y N N
Y N N N Y N
Y Y N Y Y Y Y
Y Y
Y Y
Y N
Y -
Y Y Y Y Y Y
Y Y Y Y Y Y
N N N N Y Y
Y Y Y Y Y Y
Y Y Y Y Y
Y Y Y Y Y
N N N N N
N N N N N
N Y Y Y Y Y
Y Y Y Y Y
N N N N Y
Y Y Y Y Y Y
Y
N
N
Y
Y Y N Y N N
Y Y N -
Y N -
Y Y Y Y Y Y
1 Dozentransport 1 Dozeninvoer 1 Draagrol 2 Indexer 1 Kettingspanner 1 Cylinder kettingspanner 2 Gaffel 3 Bus 4 Smoorventiel 5 Slijtplaat 6 Reactie arm 7 Flenslager 8 Pen, M12 X 50 9 Veer ring 2 Dozenwip 1 Ketting 2 Kettingwielen 3 Curveschijf 4 Curverol 3 Flenslager 4 Begeleidingsrol 5 Kraagbus 3 Dozendoorvoerketting 1 Ketting (2x) 1 Kettingwielen 2 Meenemers 1 Achterste meenemer 2 Voorste meenemer 3 Vulplaat 4 Stalen meenemer 3 Flenslager 4 Flenslager 5 Kettinggeleidingen 1 Verbindingsstuk 2 Verlenging geleiding top 3 Geleiding top 4 Geleiding bottom 5 Verlenging geleiding bottom 4 Aandrijving 1 Servo motor 1 Reductor - RH 2 Koppeling - dempingsster 2 Aandrijfas dozendoorvoerketting 3 Klembus 4 Duplex ketting 5 Doos afsteller 1 Lengteverstelling doos 2 Breedteverstelling zijgeleiding 1 Ketting 2 Tandwielen 3 Knop 3 Dekplaat cylinder 4 Borgmoer RH 5 Borgmoer LH
102
6 Afstelring 7 BEARING, CASE, ADJ 6 Dozenuitvoer 1 Uitvoerrollen 2 Centreerpennen 2 Flessentransport 1 Flesseninvoer 1 Flesseninvoertafel 1 Bochtenketting 2 Bochtenkettingwiel 3 Meeloopwiel 4 Kunststof flessenmat 5 Kettingwiel flessenmat 6 Ketting geleider 7 Kettingwielen 8 Aandrijving flessenketting 9 Aandrijving flessenmat 10 Overgangsplaat flessenmat 11 Flenslagers 12 Kettinggeleider 13 Servo motor 1 Reductor 14 Kettingwielen 15 Ketting 2 Flessenlaantjes 1 Flesgeleidingen 2 Flesgeleidingen 3 Inloopvinnetjes 4 Spacers 5 Klem spacers 2 Onderste flessenstop 1 Montagebeugel 2 Cylinder 3 Gaffel 4 Montageplaat 3 Anti-kantel mechanisme 1 Gaffel 2 Cylinder 3 Smoorring 4 Gaffel 5 Vork 6 Kogelgewricht 7 Gaffelpen, M12 x 30MM 3 Inpaktafel 1 Lift systeem 1 Servo motor 1 Reductor 2 Koppeling - sterretje 2 Ketting 3 Kettingwielen 4 Taperlock 5 Veren kettingspanner 6 Geleideblokken 7 Aandrijfas lift 8 Flenslager 9 Klembus 10 PLATE, MOUNT, SERVO 2 Demptafel 1 Schokdemper 2 Geleideblok 3 Cover plaat plateau 4 Demperplaat 3 Lift stel 1 Klem 4 Trekstang 1 Aandrijving 1 Servomotor 1 Reductor
103
Y N
N -
N -
Y Y
Y Y
Y N
N -
Y Y
Y Y Y Y Y Y Y N N Y Y Y N Y Y Y
Y Y Y Y Y N Y Y Y Y Y Y Y
N N N N N N N Y N N N Y
N N Y N N N N Y Y Y Y Y Y Y N Y
Y Y Y N N
Y Y Y -
N N N -
N N Y -
N Y Y N
Y Y -
Y N -
Y Y Y -
Y Y N Y Y Y Y
Y Y Y N N N
N Y N N N N
Y Y Y Y Y Y Y
N Y Y Y Y Y Y Y Y Y Y Y
Y Y Y Y N N Y N Y N N
N N Y N N N Y N N
Y Y Y Y Y Y Y Y Y Y Y Y
Y Y Y Y
Y Y N N
N N -
Y Y Y Y
N Y
N
-
-
N Y
Y
N
Y
2 Koppeling 2 Tandriem 3 Tandriemwielen 4 Lagerblok airbags 5 As meeloopwiel 6 Aandrijfas trekstang 7 Aandrijfas trekstang 8 Aandrijfas trekstang 9 Koppeling aandrijfas trekstang 10 Liniear lager 11 Keer ring 12 Borging 2 Inlooplaantjes 1 Airbag 2 Airbag 3 Airbag 3 Bevestigingsplaat 5 Valplaat 1 Flessenstop 1 Onderste flessenstop 2 Stop blok 3 Stopper 4 Bevestigingsbout 2 Luchtcylinder 3 Demper 4 Slijtstrip 1 Slijtstrip voorkant 2 Bevestiging slijtstrip 3 Slijtstrip achterkant 5 Vulring 6 Veer 7 Fitwerk 1 Nippen 2 Stop H-655 3 Stop H-657 8 Schroefdraad koppeling 9 Demper 10 Flappenspreider 11 Overgangsplaat 6 Grid 1 Luchtcylinder 2 Gridvinger 3 Gridveertje 4 Grid pen 5 Vorkplaat 6 Schroefdop 7 Kam 8 Conus kegel 9 Bevestigingsring 1 O-ring 2 D-ring 10 Bus 11 Bus 12 Blokgeleiding 13 Fitwerk 1 Snelkoppeling H-542 2 Snelkoppeling H-179 14 WASHER, FLAT, 1/2 15 WASHER, FLAT, 5/16 16 BUSHING, TRANS BAR 17 BUSHING, TRANS BAR 18 Overgangsplaat 1 Bevestigingsplaat 2 Bevestigingsplaat 3 Sleeve 4 Bus 5 Montageplaat 6 Verbindingsstrip plaat
104
Y Y Y Y N N N N Y Y Y Y
Y Y Y Y Y Y N N
N N N Y N Y -
Y Y Y Y Y Y Y Y
N N N N
-
-
-
N N N N N Y
N
-
Y
N N N N Y
Y
N
Y
N N N N Y N N
N -
-
Y -
N N N N N N N N
-
-
-
Y Y Y Y Y
Y Y N N Y
N N N
Y Y Y Y Y
N N N N N N
-
-
-
Y Y Y N N Y
Y Y Y Y
N N N N
Y Y Y Y
7 Verzorgingsunit schakelventielen 1 Ventielen 1 Magneetventiel 2 Magneetventiel 3 Magneetventiel 4 Magneetventiel 5 Reduceerventiel 6 Filter, vacuum 8 Algemeen 1 Servo benodigdheden 1 Servo kabel C-1288 2 Servo kabel C-1289 2 Interface printkaart 3 Schakelaar 1 micro schakelaar 18pa1 2 micro schakelaar 201cs1 4 Fotocellen 1 Fotocel WL36-B230 2 Fotocel PRK 97/4L 5 Overkapping 1 Gasveer
105
N N N N N Y
Y
N
Y
N N N
-
-
-
N N
-
-
-
N N
-
-
-
Y
N
-
Y
APPENDIX M MATHEMATICAL FORMULATIONS TMC This appendix will provide the mathematical formulations of the general Total Maintenance Costs (TMC) calculations (as provided in section 9.4.1) and their input formulas. Table 29 provides a list of definitions of the different variables used in this appendix. After each formula, the newly used parameters are explained. TABLE 29: DEFINITION PARAMETERS APPENDIX M
Notation Ce Ci Cm Cp Cs Cu E[d]p E[d]u E[i] E[m] E[r]p E[r]u G(.) M(.) re rp ru T TMCAge TMCBlock TMCCBM-PI TMCCM TMCPR-PM V W Y Z
Definition Investment in measurement equipment (once only) Cost of one inspection of the condition of the component. Cost of one measurement of the condition of the component. Cost of one planned replacement of the component Cost of one spare part of the component. Cost of one unplanned replacement of the component. Expected downtime per planned replacement of the component. Expected downtime per unplanned replacement of the component. Expected time required for one inspection of the condition of the component. Expected time required for one measurement of the condition of the component. Expected replacement time of one planned replacement of the component. Expected replacement time of one unplanned replacement of the component. Probability that the deteriorated state is not detected. The expected number of replacements, during the interval 0 until . Rate of the maintenance expert per hour. Rate of one hour planned downtime of the production line. Rate of one hour unplanned downtime of the production line. Time horizon or production hour horizon (depending on the maintenance policy) that is considered, from 0 until T. Total cost of maintenance of the preventive age dependent policy Total cost of maintenance of the preventive block policy Total cost of maintenance of CBM – periodic inspection Total cost of maintenance of the corrective maintenance policy Total cost of maintenance of Predictive maintenance – periodic measurements Inspection interval (for Predictive maintenance) Inspection interval (for CBM periodic inspection policy) Policy parameter for the block policy; the preventive maintenance interval Preventive maintenance age (for TBM age policy)
Measure Euro (€) Euro (€) Euro (€) Euro (€) Euro (€) Euro (€) Hours Hours Hours Hours Hours Hours Probability Number Euro (€) per hour Euro (€) per hour Euro (€) per hour Days Euro (€) Euro (€) Euro (€) Euro (€) Euro (€) Days or production hours Days or production hours Days Days
M 1. INPUT TMC FORMULAS In section 9.4.1 are the general input calculations for the TMC presented. In this section, their mathematical formulation is given. Parameters used are provided in Table 29. The cost of one planned replacement (
) can be calculated by: [ ]
[ ]
(M.1)
Where [ ] is defined as the expected time required for a planned replacement, which is multiplied by the costs of one hour of the maintenance expert ( ). The costs of planned downtime are calculated by the expected planned downtime ( [ ] ) times , which is defined as the costs of one hour planned downtime. Additionally, the costs of the spare component notated as The cost of one unplanned replacement, notated as
.
, can be calculated in a similar way: 106
[ ]
[ ]
(M.2)
The calculation is similar to formula (M.1). Now, [ ] is the expected time required for an unplanned replacement. [ ] is defined as the expected downtime of an unplanned replacement and are the costs of unplanned downtime per jour. The costs of one periodic inspection ( ) are formulated as: []
(M.3)
The costs of one inspection are calculated by the expected time of one inspection ( [ ]) multiplied by the hourly costs of the maintenance expert ( ). The costs of one measurement of the condition of the component (
) can be calculated according:
[ ]
(M.4)
With [ ] defined as the expected time required for the measurement of one component.
M 2. TOTAL MAINTENANCE COST PER MAINTENANCE POLICY This section provides the abstract mathematical formulas to calculate the TMC for each maintenance policy, as are provided in section 12.4.1.
M 2.1. TMC CORRECTIVE MAINTENANCE The TMC of applying corrective maintenance to a component can be calculated according: ( )
(M.5)
In this formula, is denoted as the total costs of maintenance applying corrective maintenance. Calculated by the costs of one unplanned replacement ( ) multiplied by the expected number of replacements during T, denoted as ( ).
M 2.2. TMC BLOCK POLICY ) is:
The formula of the TMC of the block policy (
( )
⁄
⁄
(M.6)
Where Y is defined as the time interval between the planned replacements; the policy parameter of the block policy. ( ) is the expected number of replacements during Y, the expected number of breakdowns before the component is preventively replaced.
M 2.3. TMC AGE DEPENDENT POLICY The TMC of the age policy (
) can be calculated by: (
( ))
( )
( )
( )
(M.7)
With Z as the age interval as the policy parameter of the age dependent policy: a component is preventively replaced when reaching age Z. ( ) is the corresponding number of expected replacements before Z is reached.
M 2.4. TMC CBM PERIODIC INSPECTIONS For the CBM policy – Periodic inspections, the TMC function is:
107
(
⁄
( ))
( )
( )
( )
(M.8)
W is the policy parameter of the periodic inspection policy which represents the inspection interval. G(W) is defined as the probability that the deteriorated state is not inspected and failure cannot be prevented.
M 2.5. TMC PREDICTIVE MAINTENANCE – PERIODIC MEASUREMENT The TMC of predictive maintenance with periodic inspections can be calculated similar as the CBM policy with periodic inspections: ⁄
(
( ))
( )
( )
( )
(M.9)
Here, V is the measurement interval and G(V) the probability of not measuring deterioration of the component and therefore the component will fail without preventive replacement.
108
APPENDIX N CALCULATIONS TMC EXAMPLE COMPONENTS This appendix provides an explanation of the calculations of the step ‘Determine optimal policy parameter value’, as discussed in section 12.4. it explains the different costs aspects that will be used in the TMC formulas, of the three example components. The general data, as provided in section 12.4.2 is shown in Table 30. In Table 31 the input information is given, required to calculate the cost of maintenance acitivities, for the possible maintenance policies of the three MSCs. TABLE 30: FIXED COSTS PACKERS LINE 7, USED AS INPUT FOR THE TMC FORMULAS
Parameter Remaining life time (T) Costs maintenance expert ( ) Costs unplanned downtime ( ) Costs planned downtime ( )
Value 10 years € 60,- per hour € 566,- per hour € 0,-
Value 120 months € 1,- per minute € 9,43 per minute € 0,-
TABLE 31: PARAMETER VALUES THREE EXAMPLE COMPONENTS PACKERS LINE 7, USED AS INPUT FOR THE TMC FORMULAS
Cylinder 60 60 90 60 35 45 € 86,21
Expected planned downtime (minutes) Expected planned replacement time (minutes) Expected unplanned downtime (minutes) Expected unplanned replacement time (minutes) Expected inspection time (minutes) Expected measurement time (minutes) Costs spare component
Dozendoorvoerketting 240 240 240 240 60 45 € 1669,55
Tandriem 240 240 250 240 10 € 29,24
With the data of Table 30 and Table 31, the costs of the several maintenance activities can be calculated, according the formulas mentioned in section 9.4.2 and APPENDIX M 1. I.e. the cost of one planned replacement of the cylinder equal: [ ]
[ ]
And the costs of one unplanned replacement of the cylinder is: [ ]
[ ]
Results of all those calculations are shown in Table 32. TABLE 32: COSTS MAINTENANCE ACTIVITIES THREE EXAMPLE COMPONENTS
Cylinder € 146,21 € 955,21 € 35,€ 45,-
Costs of one planned replacement Costs of one unplanned replacement Costs of one inspection Costs of one measurement
109
Dozendoorvoerketting € 1.909,55 € 4.173,55 € 60,€ 45,-
Tandriem € 269,24 € 2.627,57 € 10,-
APPENDIX O TMC ALL MSCS FOR POSSIBLE MAINTENANCE POLICIES This appendix is the result of the step ‘Determine optimal policy parameter value’, as discussed in section 0, provides the lowest TMC for each possible maintenance policy of each MSC. Those values are shown in Table 33. Additionally, the result of the step ‘Determine maintenance policy per MSC’ is executed as mentioned in section 12.5. The result of that step is also shown in the table below; the green box is the lowest TMC for that component and will be included in the maintenance concept. The amount of components in the technical system is taken into account in the TMC calculations. TABLE 33: TMC FOR ALL POSSIBLE MAINTENANCE POLICIES PER MSC
Dozeninpakker 71&72 1 Dozentransport 1 Dozeninvoer 1 Draagrol 2 Indexer 1 Kettingspanner 1 Cylinder kettingspanner 2 Gaffel 3 Bus 4 Smoorventiel 5 Slijtplaat 6 Reactie arm 7 Flenslager 8 Pen, M12 X 50 9 Veer ring 2 Dozenwip 1 Ketting 2 Kettingwielen 3 Curveschijf 4 Curverol 3 Flenslager 4 Begeleidingsrol 5 Kraagbus 3 Dozendoorvoerketting 1 Ketting (2x) 1 Kettingwielen 2 Meenemers 1 Achterste meenemer 2 Voorste meenemer 3 Vulplaat 4 Stalen meenemer 3 Flenslager 4 Flenslager 5 Kettinggeleidingen 1 Verbindingsstuk 2 Verlenging geleiding top 3 Geleiding top 4 Geleiding bottom 5 Verlenging geleiding bottom 4 Aandrijving 1 Servo motor 1 Reductor - RH 2 Koppeling - dempingsster 2 Aandrijfas dozendoorvoerketting 3 Klembus 4 Duplex ketting 5 Doos afsteller 1 Lengteverstelling doos 2 Breedteverstelling zijgeleiding 1 Ketting 2 Tandwielen 3 Knop
Corrective Maintenance
€
Block policy
Agedependent policy
Periodic inspection
Periodic measurement
885,90
€ 9.952,10 € 9.177,30 € 8.461,77 € 1.267,88 € 8.634,08 € 2.288,22 € 15.061,32 € 1.232,28 € 6.108,40
€ € € € € € € € €
7.140,94 3.210,06 1.761,28 643,03 3.381,86 1.023,80 3.729,32 895,53 3.340,16
€ € € € € € € € €
6.263,68 3.072,60 1.669,77 588,68 3.151,60 950,03 3.544,65 832,85 3.160,80
€ €
9.862,10 5.487,30
€
4.642,08
€
4.177,32
€
8.827,32
€ 10.610,00 € 7.952,00 € 4.618,00 € 3.112,95 € 12.421,25 € 1.282,00 € 4.127,08
€ 10.255,00 € 2.900,00 € 1.788,00 € 1.124,84 € 4.206,56 € 588,13 € 1.149,69
€ €
7.780,00 2.900,00
9.900,00
1.061,18 3.931,25 541,25 1.096,63
6.550,00 2.760,00 3.388,00 1.882,95 4.701,25
€
€ € € €
€ € € € €
€ 20.867,75 € 9.884,80
€ 23.269,05 € 3.852,53
€ 21.359,50 € 3.645,33
€ 16.747,75 € 5.628,80
€ € € € € €
10.246,72 11.251,14 10.122,82 22.592,00 4.416,53 4.281,33
€ 4.690,50 € 6.259,91 € 4.496,91 € 12.660,00 € 2.851,47 € 2.648,67
€ 4.318,40 € 5.573,93 € 4.163,53 € 11.260,00 € 2.529,87 € 2.394,67
€ € € € € €
€ € € € €
50.408,90 13.775,60 27.540,00 13.770,00 6.986,83
€ € € € €
5.128,90 2.455,60 4.900,00 3.827,00 2.025,51
€ 12.725,25
€ 15.097,75
€ €
5.593,20 5.458,00
€
5.711,37
€
789,60
€ 28.368,90 € 8.265,60 € 16.520,00 € 8.410,00 € 4.306,83
€ 8.752,80 € 5.999,67 € 5.645,62 € 11.074,10 € 297,18 € 6.204,70
€ 10.765,94 € 5.163,16 € 7.075,22 € 419,88 € 4.191,75
€ € € € €
6.910,00 4.466,45 6.263,10 358,53 3.919,40
€
2.348,40
€
7.214,00
€
5.564,00
€ € €
829,20 1.496,40 478,63
€ €
776,40 709,40
€ €
726,40 686,40
110
1.190,72 2.195,14 1.066,82 4.480,00 3.773,20 1.708,00
€ 13.262,10
€ € € € €
7.285,22 5.459,51 8.544,10 338,23 6.461,37
€ €
813,36 1.193,04
3 Dekplaat cylinder 4 Borgmoer RH 5 Borgmoer LH 6 Afstelring 7 BEARING, CASE, ADJ 6 Dozenuitvoer 1 Uitvoerrollen 2 Centreerpennen 2 Flessentransport 1 Flesseninvoer 1 Flesseninvoertafel 1 Bochtenketting 2 Bochtenkettingwiel 3 Meeloopwiel 4 Kunststof flessenmat 5 Kettingwiel flessenmat 6 Ketting geleider 7 Kettingwielen 8 Aandrijving flessenketting 9 Aandrijving flessenmat 10 Overgangsplaat flessenmat 11 Flenslagers 12 Kettinggeleider 13 Servo motor 1 Reductor 14 Kettingwielen 15 Ketting 2 Flessenlaantjes 1 Flesgeleidingen 2 Flesgeleidingen 3 Inloopvinnetjes 4 Spacers 5 Klem spacers 2 Onderste flessenstop 1 Montagebeugel 2 Cylinder 3 Gaffel 4 Montageplaat 3 Anti-kantel mechanisme 1 Gaffel 2 Cylinder 3 Smoorring 4 Gaffel 5 Vork 6 Kogelgewricht 7 Gaffelpen, M12 x 30MM 3 Inpaktafel 1 Lift systeem 1 Servo motor 1 Reductor 2 Koppeling - sterretje 2 Ketting 3 Kettingwielen 4 Taperlock 5 Veren kettingspanner 6 Geleideblokken 7 Aandrijfas lift 8 Flenslager 9 Klembus 10 PLATE, MOUNT, SERVO 2 Demptafel 1 Schokdemper 2 Geleideblok 3 Cover plaat plateau 4 Demperplaat 3 Lift stel 1 Klem 4 Trekstang
€ € € € €
1.568,78 2.299,80 2.293,14 2.122,20 3.994,13
€
1.091,94
€
1.015,05
€
795,53
€
742,50
€ 14.594,16 € 2.347,52
€ €
5.823,38 838,00
€ €
5.507,70 811,90
€ 13.437,58 € 47.570,53 € 3.134,05 € 21.135,42 € 476.115,33 € 21.816,40 € 23.804,77 € 1.909,00 € 1.909,00 € 3.205,00 € 11.157,60 € 4.941,45 € 9.318,80 € 5.999,67 € 9.518,67 € 1.847,33
€ 20.021,21 € 64.279,33 € 4.350,25 € 30.210,42 € 644.843,33 € 14.921,00 € 32.237,17
€ 66.548,33 € 65.546,83 € 14.837,50 € 5.574,00 € 3.426,54
€ 24.227,08 € 22.975,21 € 2.858,75
€ €
€ € €
€
4.046,20
€
2.210,16
€ 1.645,91 € 7.377,20 € 504,05 € 2.268,75 € 90.182,00 €
3.708,10
2.352,50 3.054,96 2.381,19
€ € €
2.165,00 2.958,00 2.241,90
€ € €
375,00 7.863,60 4.635,83
€ 10.765,94 € 2.193,22 € 1.045,47
€
6.910,00
€
977,87
€ € €
7.285,22 8.583,83 1.733,67
€
2.790,00
€ € €
7.590,00 6.588,50 687,50
1.004,66 515,38
€ €
939,05 476,65
€ €
1.539,28 1.506,78
€ €
2.368,70 1.004,66
€ €
2.068,25 939,05
€ €
4.103,50 1.639,28
€ € € €
926,12 1.059,68 1.239,62 816,05
€ € € €
866,10 977,40 1.127,35 774,38
€
2.901,35
€ € € €
3.270,05 1.743,03 1.608,65 1.722,55
€ € € € € € €
4.332,25 1.743,03 217,64 3.130,10 3.241,40 3.391,35 3.038,38
€ € € € € € € € € € € €
8.147,60 4.003,97 5.645,62 9.560,00 42.301,33 6.794,10 12.433,65 8.156,50 7.822,50 50.471,00 16.551,13 4.163,33
€ 6.400,34 € 5.163,16 € 4.378,00 € 12.966,13 € 3.627,02 € 3.470,67 € 5.808,65 € 5.889,50 € 15.429,10 € 3.112,91 € 1.749,67
€ 4.415,38 € 4.466,45 € 4.183,00 € 12.529,33 € 3.400,20 € 3.359,30 € 5.559,00 € 5.457,00 € 14.910,00 € 2.967,13 € 1.616,33
€ 5.289,52 € 5.459,51 € 9.216,67 € 32.056,89
€ 50.940,00 € 20.249,55 € 8.896,67 € 8.525,17
€ 19.527,00 € 5.294,51 € 2.239,67 € 1.831,02
€ 18.678,00 € 4.967,55 € 2.104,67 € 1.733,17
€ 22.180,00 € 8.469,55
€
1.167,68
111
€
3.296,50
€
6.791,00
€
7.369,60
€
1.392,67
€
2.339,28
€
2.339,28
€ 10.566,67
€ 12.541,00
1 Aandrijving 1 Servomotor 1 Reductor 2 Koppeling 2 Tandriem 3 Tandriemwielen 4 Lagerblok airbags 5 As meeloopwiel 6 Aandrijfas trekstang 7 Aandrijfas trekstang 8 Aandrijfas trekstang 9 Koppeling aandrijfas trekstang 10 Liniear lager 11 Keer ring 12 Borging 2 Inlooplaantjes 1 Airbag 2 Airbag 3 Airbag 3 Bevestigingsplaat 5 Valplaat 1 Flessenstop 1 Onderste flessenstop 2 Stop blok 3 Stopper 4 Bevestigingsbout 2 Luchtcylinder 3 Demper 4 Slijtstrip 1 Slijtstrip voorkant 2 Bevestiging slijtstrip 3 Slijtstrip achterkant 5 Vulring 6 Veer 7 Fitwerk 1 Nippen 2 Stop H-655 3 Stop H-657 8 Schroefdraad koppeling 9 Demper 10 Flappenspreider 11 Overgangsplaat 6 Grid 1 Luchtcylinder 2 Gridvinger 3 Gridveertje 4 Grid pen 5 Vorkplaat 6 Schroefdop 7 Kam 8 Conus kegel 9 Bevestigingsring 1 O-ring 2 D-ring 10 Bus 11 Bus 12 Blokgeleiding 13 Fitwerk 1 Snelkoppeling H-542 2 Snelkoppeling H-179 14 WASHER, FLAT, 1/2 15 WASHER, FLAT, 5/16 16 BUSHING, TRANS BAR 17 BUSHING, TRANS BAR 18 Overgangsplaat 1 Bevestigingsplaat 2 Bevestigingsplaat 3 Sleeve
€ € € € € € € € € € € € € €
9.348,80 3.577,79 2.258,25 13.137,84 30.280,00 9.991,30 8.425,00 12.098,33 12.098,33 12.098,33 6.485,00 28.465,07 27.225,67 6.761,67
€ € € € €
8.700,03 3.751,76 4.006,13 6.988,00 9.659,13
€ € € € €
6.586,13 3.287,28 3.871,52 6.790,00 7.868,80
€ 2.298,50 € 13.569,81 € 10.843,13 € 2.612,33
€ 2.216,00 € 12.782,13 € 10.303,33 € 2.486,33
€ € € € €
4.863,34 3.543,80 3.746,18 2.380,00 9.919,63
€ 3.855,00 € 16.601,73
€ 22.320,40 € 74.138,40 € 22.320,40 € 2.684,00
€ € € € € €
949,52 3.447,27 859,57 995,79 2.405,43 6.232,93
€
9.812,37
€
8.348,53
€ € € € €
596,63 310,19 721,25 535,85 1.153,76
€
475,80
€
439,76
€ € € € € € €
253,33 112,78 116,36 476,69 1.405,73 6.973,33 542,53
€
743,55
€
651,07
€ € € € €
6.021,88 5.217,33 1.464,08 351,38 2.616,99
€ € € € €
€ € €
448,08 596,64 394,89
€ € €
€
840,43
5.412,50 4.689,53 1.356,32 332,10 2.243,72
€ €
4.237,50 3.671,20
€
3.466,38
411,64 546,69 361,92
€ € €
1.114,47 1.249,53 829,75
€ 1.975,43 € 49.002,50 € 144.739,47 € 2.580,87 € 73.920,13 € 72.947,33 € 5.789,73 € 73.015,73 € 14.337,50 € 12.424,53 € 3.864,32 € 1.586,10 € 3.753,05 € € € € € €
314,69 278,89 2.490,12 2.487,62 785,88 260,87
€ € €
836,14 971,19 651,42
112
€ 18.151,73
4 Bus 5 Montageplaat 6 Verbindingsstrip plaat 7 Verzorgingsunit schakelventielen 1 Ventielen 1 Magneetventiel 2 Magneetventiel 3 Magneetventiel 4 Magneetventiel 5 Reduceerventiel 6 Filter, vacuum 8 Algemeen 1 Servo benodigdheden 1 Servo kabel C-1288 2 Servo kabel C-1289 2 Interface printkaart 3 Schakelaar 1 micro schakelaar 18pa1 2 micro schakelaar 201cs1 4 Fotocellen 1 Fotocel WL36-B230 2 Fotocel PRK 97/4L 5 Overkapping 1 Gasveer
€ € €
1.247,63 2.519,63 301,83
€
267,87
€
226,37
€
307,50
€ € € € € €
727,30 925,68 1.308,40 1.437,40 1.076,16 2.843,33
€
1.648,25
€
1.576,50
€
2.200,00
€ € €
3.756,16 3.729,68 6.779,49
€ €
1.255,12 1.359,48
€ €
1.485,90 1.187,50
€
2.823,80
€
3.529,75
€
2.823,80
113
APPENDIX P CLUSTERING MAINTENANCE ACTIVITIES In this appendix, the clustering of the maintenance activities of the assemblies: dozenwip, anti-kantel mechanisme and demptafel is provided, in addition of the clustering of maintenance activities of the kettingspanner, as explained in section 12.7.
P 1.
CLUSTERING ASSEMBLY DOZENWIP
The components and the maintenance concept of the dozenwip are provided in Table 34. As mentioned in Table 13, maintenance activities of the dozenwip have a start-up time of 30 minutes. TABLE 34: MAINTENANCE CONCEPT DOZENWIP
Component
Maintenance policy
Interval
Maintenance Amount per expert time packer Ketting Periodic inspections 6 months 40 minutes 2 Kettingwielen Periodic inspections 12 months 40 minutes 4 Curveschijf Block policy 200 months 480 minutes 1 Curverol Periodic inspections 3 months 60 minutes 1 It is expected that the curveschijf will keep functioning during the remaining lifetime of the packers; therefore, that component is not taken into account in the clustering. The curverol has the shortest inspection interval; each 3 months the curverol should be inspected. This inspection could be combined with the inspections of the ketting and the kettingwielen. This saves:
Concluding, by clustering the maintenance activities of the components of the dozenwip, â&#x201A;Ź2.400,- can be saved per packer during T; â&#x201A;Ź4.800,- on the total maintenance budget of both packers during T.
P 2.
CLUSTERING ASSEMBLY ANTI-KANTEL MECHANISME
The components and the maintenance concept of the anti-kantel mechanisme are provided in Table 35. As mentioned in Table 13, the dozenwip has a start-up time of 20 minutes. TABLE 35: MAINTENANCE CONCEPT ANTI-KANTEL MECHANISME
Component
Maintenance policy
Interval
Maintenance Amount expert time per packer Gaffel Age-dependent policy 24 months 30 minutes 1 Cylinder Age-dependent policy 24 months 45 minutes 1 Smoorring Corrective maintenance 1 Gaffel Age-dependent policy 24 months 30 minutes 1 Vork Age-dependent policy 24 months 30 minutes 1 Kogelgewricht Age-dependent policy 24 months 30 minutes 1 Gaffelpen Age-dependent policy 24 months 30 minutes 1 In section 12.7 is already explained that clustering is not applies at components with that are maintained according the age-dependent policy, because their replacement moment can vary over time. Since all maintenance components of the anti-kantel mechanisme are maintained according the age-dependent policy, it is researched for which one it is profitable to change the maintenance policy to the block policy and cluster the maintenance activities. The extra costs of applying the block policy and the possible savings of it is shown in Table 36.
114
TABLE 36: POSSIBLE SAVINGS PER PACKER THROUGH CLUSTERING COMPONENTS ANTI-KANTEL MECHANISME
Component
Block Age-dependent Extra costs Possible Result policy policy block policy savings Gaffel € 1.802,70 € 1.502,25 € 300,45 €100,-€ 200,45 Cylinder € 721,66 € 656,05 € 65,61 €100,€ 34,39 Gaffel € 360,12 € 300,10 € 60,02 €100,€ 39,98 Vork € 493,68 € 411,40 € 82,28 €100,€ 17,72 Kogelgewricht € 673,62 € 561,35 € 112,27 €100,-€ 12,27 Gaffelpen € 250,05 € 208,38 € 41,68 €100,€ 58,32 The total saving for one packer during T can be €150,41 by clustering the activities of the cylinder, the gaffel, the vork and the gaffelpen according the block policy. However, the start-up of this clustered maintenance activity is 20 minutes and costs €100,- during T (5 times start-up during T). Thus, the savings of the maintenance budget is €100,82 for both packers during T.
P 3.
CLUSTERING ASSEMBLY DEMPTAFEL
The components and the maintenance concept of the demptafel are provided in Table 37. As mentioned in Table 13, the demptafel has a start-up time of 45 minutes. TABLE 37: MAINTENANCE CONCEPT DEMPTAFEL
Component
Maintenance policy
Interval
Maintenance Amount per expert time packer Schokdemper Age-dependent policy 12 months 80 minutes 4 Geleideblok Age-dependent policy 24 months 80 minutes 4 Cover plaat Age-dependent policy 24 months 60 minutes 2 Demperplaat Age-dependent policy 24 months 60 minutes 2 Since all maintenance components of the anti-kantel mechanisme are maintained according the agedependent policy, it is researched for which one it is profitable to change the maintenance policy to the block policy and cluster the maintenance activities. The extra costs of applying the block policy and the possible savings of it is shown in Table 36. TABLE 38: POSSIBLE SAVINGS PER PACKER THROUGH CLUSTERING COMPONENTS DEMPTAFEL
Component
Block policy
AgeExtra costs Possible Result dependent block policy savings policy Schokdemper € 19.527,00 € 18.678,00 € 849,00 € 1.800,- € 951,00 Geleideblok € 5.294,51 € 4.967,55 € 326,96 € 900,€ 573,04 Cover plaat € 2.239,67 € 2.104,67 € 135,00 € 450,€ 315,00 Demperplaat € 1.831,02 € 1.733,17 € 97,85 € 450,€ 352,15 Changing the maintenance policy to the block policy for all 4 components of the assembly demptafel saves € 2.191,19. However, start-up costs should be paid every year for the replacement of the schokdempers, €450,during T. Thus, the saving for one packer is € 1.741,19; € 3.482,38 on the maintenance budget of both packers during T. The results of this appendix are shown in Table 16 in section 12.7.
115
APPENDIX Q PLANNING MAINTENANCE ACTIVITIES In section 12.8, the planned maintenance activities of the block policy and the periodic inspections and measurements are grouped, in order to have as little as possible maintenance cards per packer. In this appendix, firstly the planning of the revisions is provided. Secondly, it is shown how to schedule the planned maintenance activities.
Q 1. PLANNING REVISION During the revision, the line is down for 2 weeks. This brings 8 hours downtime for 5 days per week with 4 maintenance experts, equalling (60*8*5*2*4) 19.200 minutes available for maintenance for both packers. Per packer 9600 minutes are available. Table 17 provided the required time of the maintenance experts per time interval for the clustered assemblies and the remaining components. Combining all activity times, Table 39 is composed. Planning those activities over the next 5 revisions during T, Figure 52 is composed. The activities repeating every revision take 1100 minutes (dark blue) and the other activities are added in the interval they have to be executed. This shows that in none of the revisions, there is a problem with the time. Even in revision 4, there are only maintenance activities for 6400 minutes so there are still (9.600-6.400) 3.200 minutes left. TABLE 39: REQUIRED MAINTENANCE DURING REVISIONS
Interval
Maintenance expert time 1100 minutes 3860 minutes 800 minutes 1440 minutes 400 minutes
Required time maintenance expert (minutes)
24 months 48 months 72 months 96 months 120 months
7000 6000 5000
120 months
4000
96 months
3000
72 months 48 months
2000
24 months 1000 0 Revision Revision Revision Revision Revision 1 2 3 4 5
FIGURE 52: PLANNING MAINTENANCE ACTIVITIES DURING REVISIONS
116
Q 2. PLANNING STOPDAY The planned maintenance activities with an interval until 12 months are planned in Figure 53. The first 24 months are shown, after that the planning can be repeated. The smallest interval is the monthly maintenance activities that require 78 minutes of the maintenance experts. So, a maintenance card is required every month. The other maintenance activities are planned together with the monthly maintenance, such that they can be executed in one stopday. On a stopday the maintenance experts are available for 1440 minutes (360 minutes for 4 maintenance experts). As can be seen in Figure 53, the only exceeding of the 1.440 minutes occurs in months 24; during the revision. That moment, 1.628 minutes of maintenance activities are planned and this can easily be combined in the revisions (even in revision 4 there were 3.200 minutes left).
Required time maintenance expert (minutes)
1800 1600 1400
Demptafel Dozenwip 12 months 3 months 1 month
Anti-kantel mechanisme Kettingspanner 6 months 2 months
1200 1000 800 600 400 200 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Month
FIGURE 53: PLANNING MAINTENANCE ACTIVITIES STOPDAY
In Figure 53, the planning is based on only one packer and as can be seen, only one stopday per month is used. For the other packer, the same planning can be applied in the other stopday of the month.
117