Human Factors

A process book describing the journey of thought to product

Human Factors A redesign of the electric hand mixer using the human factor research and design method.

IDUS 221 || Spring 2009

Lien || Metivier || Tu

Overview

Human Factors The underlying focus

“

Exploring the physical, psychological, perceptual and behavioral characteristics of humans. Through a series of lectures and projects, this information is applied to the field of industrial design to develop safe and effective products.

�

Savannah College of Art and design, IDUS 221 Course Description

3

Research: Research: Physical && Physical Market Market

1

Pre - Design: Ideation & Mock-Ups

2

Useability Testing

3

Final Model

4

Anthropometrics

Design Criteria

Demographic profile

Build

Anatomy

Sketching

Questionnaire

Refine

Market Research

Modeling

Market Research

Finish

Field Research

Final Model

Field Research

Contents

Each step along the way

5

Overview

Research: Physical & Market

7

Research: Physical & Market

1 Anthropometrics Anatomy Market Research Field Research

Chapter 1 || Introduction

We start at the beginning..

How to go about conducting a design process while applying the human factors method • •

The first step is to look at the natural traits of the intended user Research of existing electric mixers

9

Everyone is different.

Learning about the sizes of ourselves , peers, and the demographic of the new product Designing a product begins by researching the user.

The process of matching the physical wants and needs of the user with the product design is an Anthropometric approach to design. The sizes gathered can be used to build a comfortable dimensions for the form of the mixer.

This analysis uses graphs to depict the relationship between the measurements and those who have been measured.

Chapter 1 || Anthropometrics Object: To show an understanding of the anatomy involved with the use of the hand mixer focusing on the lengths of the body parts involved with using the mixer.

11

Object: To show and understanding of the anatomy involved with the use of the hand mixer focusing on the muscles, tendons, and bones, and medical problems that would limit the use the mixer.

Chapter 1 || Anatomy, Injury, and disability

Our strengths & weaknesses A further look into the physical make-up of the intended demographic. Focusing on the standard and inhibited user Such an appliance can be difficult to use for the average, but also to those who may be medically impaired. This study focuses on personal injury and how it affects the redesign of the hand mixer.

Close observation of the muscles, tendons, and bones offers a substantial amount of information which is vital to creating an optimal product.

13

What has been done?

Finding necessary functions needed to operate a hand mixer as well as learning about the current standards of the appliance To develop a strong grasp of what is considered to be normal to the design of our product, an analysis was conducted . This exercise furthered the understanding of a several key concepts: • Vent - shape (horizontal line shaped) • Vent - position (half way up the unit) • Eject button (above handle and hard to push) • Power cord - runs off the side (so mixer can sit while idle) • Power button - position, size (above handle, large size)

Chapter 1 || Market Research Functions and the average locations for each characteristic that makes up the general hand mixer on the market.

15

Chapter 1 || Fatigue Test

Questioning Fatigue The group built a rig to ask some basic questions about mixer • To learn about what muscles become fatigued while mixing • Find measurable wrist angles and heights while mixing • To learn how to use existing mixers

The test was taken on fifteen students. Each tester held the rig simulating weight as if mixing a batter. The primary objective was to learn about: • The point of fatigue: women felt fatigue after one minute, males felt fatigued after a minute and a half • The muscles that primarily get fatigued; shoulder and arm

17

Height and Angle Test The goal was to play around with different heights and angles

This test was taken on eleven students. Each tester used a mixer at four different table heights . The primary objective was to learn about:

Results: • Comfortable shoulder angle range: 90 - 100 degrees • Comfortable elbow angle range: 80 - 120 degrees • Comfortable wrist angle range: 10 - 20 degrees • Comfortable table height range:

31” to 33” for females 33” - 36” for males

Chapter 1 || Height & Angle Test

19

Starting on the left: A close up of a detail explaining the location of the mixing blades. Each mixer was analyzed in turn for specific strengths and weakness. Target was chosen for the field research.

Chapter 1 || Field Research

Farming in the field Research was intensified by a trip to Target to get a first hand experience of successful mixers

The purpose was to concentrate on aspects that needed to be analyzed. These purposes included: • Weight - center of balance • Open backed handles compared to closed handles • Stiffness of buttons

21

Some Experimentation A quick survey of the targeted demographic

Some basic questions were asked tofifteen females. The answers to these questions helped the launch into the ideation phase.

Chapter 1 || Brief Survey

What do you expect from a perfect hand mixer?

• Light color (white) • Organic shape • Small size • Easy to clean

What function do you care most about?

(Comfort, price, shape, color, size, sound/noise, vibration, or weight) • Weight • Comfort • Size • Noise

What kinds of problems do you face with current mixers?

• Hard to hold • Wrong button position • Hard to clean

If you could design a mixer, what features would you add to it?

• Don’t need to hold it • Changeable handle size • Combine mixer functions • Decrease noise and weight

23

Here is what we know and where we stand The sum that is greater than its parts.

The areas and key medical diagnoses of the human body that affect the operation of the electric hand mixer. These include: •

Body measurements:

Hand length, palm length, thumb length, index finger length, middle finger length, middle finger length, ring finger length, little finger length, thumb breadth, thumb thickness , Index finger breadth, Index finger thickness, metacarpal hand breadth, hand breadth across thumb, minimum hand breadth, metacarpal hand thickness, hand thickness including thumb, maximum grip diameter, maximum spread, maximum functional spread, shoulder height, elbow height, bideltiod shoulder breadth, shoulder-elbow length, elbow-fingertip length, upper limb length, shoulder-grip length, vertical grip length, standing vertical grip reach, and forward grip reach.

•

Muscles & tendons :

Chapter 1 || Summery

Deltoid, pectoralis major, tendon of triceps brachii, brachioradalis, abductor pollicis longus, flexor carpi radialis, flexor carpi ulnaris, and ectensor pollicic brevus.

•

Required bones:

Clavicle, scapula, humerus, ulna, radius, carpus, metacarpus, phalanges.

•

Medical limitations :

Arthritis, bursitis, tendonitis, carpal tunnel

•

Existing market mixer designs:

•

Fatigue Testing:

•

Field testing knowledge:

Vent shape (horizontal line shaped), vent position (half way up the unit), eject button (above handle and hard to push), power cord runs off the side (so mixer can sit while idle), and power button position, size (above handle, large size).

Shoulder and arm feel fatigue in women only one minute after mixing with a one pound rig. Males feel fatigue after one and a half minutes.

• Height and angle test: Comfortable range of: shoulder angle - 90 - 100 degrees, elbow angle - 80 - 120 degrees, wrist angle - 10 - 20 degrees, table height - 31” - 33” for females and 33” - 36” for males

Center of balance triggers some wrist fatigue, open backed handles are harder to adjust positioning compared to closed handles, and stiffness of buttons almost unusable.

• Brief survey: Preferences - Light color (white), organic shape, small size, easy to clean Important functions - Weight, comfort, noise, size Current problems - Hard to hold, wrong button position, hard to clean Ideal features - Don’t need to hold, changeable handle size, combine mixer functions, decrease noise and weight

25

Overview

Ideation and Mock-Ups

27

Pre - Design: Ideation & Mock-Ups

2 Design Criteria Sketching Modeling

Chapter 2 || Introduction

All the pawns are in position Now that there is a strong base of each component needed to design the mixer, the next goal is to begin to manipulate and organize the data.

• Use information from chapter 1 to build a cohesive outline of traits needed in the redesign • Sketch a series of drawings based on the formed criteria • Refine sketches into four measured out design drawing • Build simple models of each refined drawing

29

Object: To show and understanding of the needed design elements, sketches were drawn to emphasize attention to the previously listed details.

Chapter 2 || Pre sketching

A pictures worth 1000 words Visualization of a complete and well rounded design

To begin working out the design, sketches were drawn paying attention to the brainstorm featured on the previous page. Each element that was implicated into the design was numbered. The numbers on the sketches correlate to the left drawing on the previous page.

31

Analysis to refinement Applying measurement to exceptional sketches to create design drawings The pre sketching uncovered strengths and weaknesses in the design. Based on the sketches, variations were merged to create drawings. These would be used to create the first round of models. Main reasoning behind the drawing decisions: • All measurements based on extreme hand sizes of the demographic • Different vents were explored • Buttons large enough for a thumb • Comfortable grip angle

Chapter 2 || The Blueprints For Sculpture Measured out models which will serve as a blueprint to first modeling phase.

33

Chapter 2 || Pink foam Modeling

Modeling the drawings The practicality of pink foam modeling

Pink foam was used for the first round of models because of its consistency. Its softness is easy to work with, allowing the team to quickly refine the designs as they evolve.

Qualities of the models: • Properly scaled • Light weight • Easy to replicate and modify

35

The prototypes Getting a grip of design characteristics such as comfort and size

Building physical models allows the group to hold and sculpt the mixers so design flaws can be analyzed. A three dimensional model also makes testing possible. These models move the team to the next chapter of design: Usability Testing.

Chapter 1 || Brief Survey

37

Here is what we know and where we stand The areas and key medical diagnoses of the human body that affect the operation of the electric hand mixer. These include:

•

Possible mixer functions:

Cord retractor, angled handle, vent, and back end needs to be flat Buttons - power, boost, speed, and eject Cord - located on side, optional retract, and placed mid way to top of mixer

•

Possible mixer measurements: Buttons - button sizes, and reachable Handle - length and diameter

Chapter 2 || Summery

•

Demographic preferences:

Button position close to handle, Weight less than two pounds, and small size Shape - simple and organic Color - white and some metal accents Handle - easy to hold, changeable, and adjustable

•

Design sketches:

Based off the list from the previous bullet, numbered sketches were created to quickly adopt or reject design ideas.

•

Refined drawings:

Key concepts were put together to create a blueprint for modeling. Measurements were added to these drawings to increase accuracy.

•

Building the pink foam models:

The pink foam models were crafted in order to further refine the design via usability testing and peer critique.

39

Overview

Usability Testing

41

Usability Testing

3 Demographic profile Questionnaire Usability testing

Chapter 3 || Introduction

Getting a feel of the mixer This chapter focuses on the user and how to develop a sound testing process as well as applying the results constructively to develop a superior product. The following topics will be discussed in this chapter: • • • •

The average user of the mixer (demographic) A questionnaire that focuses on design concerns First and second rounds of testing Last round of testing

43

Who are we looking at?

Building a demographic profile for the hand mixer. What kind of person will use the mixer?

This profile works as a mental and visual cue concerning who the design is being made for.

Chapter 3 || Demographic Profile Left: A list of design elements that focus on functions, measurements, and the demographic needs. Right: A visual depiction of each element. Both: demographic is represented using blue, measurements in red, and functions are green.

45

Each Test:

2 models

Weighted equally Same mixing bowl

Location:

Leopold’s Ice Cream Parlor Surface:

Table (same size) User requirements: Standing

Orthographic photos from the same location Equipment:

2 mixers with the same weight applied

Bowl – device used to put the mixer into context

Table – surface needed to simulate a kitchen counter

Camera – take pictures of angle mixer is being held at

Weights – one kg will be placed under each mixer for weight Arrangement of test site: Arrange mixers in order on the desk where the test will take place. The table will simulate a kitchen counter.

Test one user at a time in an isolated manner from other testers from building a bias.

Testing procedure: Ask the users to speak aloud regarding their thoughts and processes throughout the test.

Ask the users to interact with each mixer, simulating the process in order and answer some questions about the product.

(See questionnaire) Take a photograph of the mixer in use.

Chapter 3 || Protocol

Survey protocol Highlighting the consistencies of the testing process.

Answering who, what, why, where, when, and how the test will be conducted.

47

What we want to learn The set of questions that would be asked to each participant of our usability testing.

The questions that the testers will be responding to will provide the team with the needed information to correctly redesign the mixer. The main ideas of focus include: • Handle comfort and angle • Button position and size (designs include two eject buttons on sides) • Cord location

Chapter 3 || Questionnaire

49

Chapter 3 || First Usability Test

First round of testing Following the protocol, data concerning the cord, handle, and buttons were collected.

The testing models were completed by using two half pound weights and dowels for mixing blades. Ten females were tested outside of Leopold’s Ice Cream Shop located in Downtown Savannah.

Design opportunities for next round of testing: • Larger buttons • Lighter weight • Focus on weight distribution • New locations for the cord

51

Second round of testing Continuing to follow the protocol, two more mixers were tested at the same location

New design opportunities include: • Widen the back so the cord can wrap around the mixer • Place cord out the back surface • Design mixer so it can still sit on its back surface • Bigger eject buttons

Chapter 3 || Second Usability Test

Chapter 3 || Third Usability Test

Rebuilding and testing again Just to be sure of the progress of the mixers evolution, a third round of testing took place

The last pink foam model was constructed and tested on five females within the target demographic. They were asked an abridged set of questions regarding the mixer. Several points were noted throughout testing: • Cord location was agreeable • Eject buttons were easy to use and correctly sized • Power button needed to be pulled closer to the hand

55

Here is what we know and where we stand Testing, altering, then repeating the process is how products are designed. This chapter explains the process the group followed to reach a final model. The process includes: •

Demographic profile:

• •

Survey protocol Questionnaire focus:

Name, age, gender, occupation, income (roughly), housing, location, marital status, children, number of people in household, left or right handed, height, hobbies, athletic activities, and favorite color

Cord location, button location and size, and the comfort and angle of the handle

Chapter 3 || Summery

• Round one of testing design opportunities:

Larger buttons, lighter weight, focus on weight distribution, and new location for the cord • Round two of testing design opportunities:

Widen the back so the cord can wrap around the mixer, place cord on back surface and still allow mixer to sit, and bigger eject buttons

•

Round three of testing design opportunities:

Cord location was agreeable, eject buttons were easy to use and correctly sized, and cord location was agreeable

57

Overview

Building the final models

59

Final Model

4 Build Refine Finish Final Model

Chapter 4 || Introduction

The final puzzle The project wraps up by completing a final models of the redesigned electric hand mixer.

• • • • • •

Crafting the final pink foam models into yellow foam Sand out imperfections Prime, paint, and finish the bodies Attach the cord and blades The final products Credits

61

Building the forms The creation of the final models required the application of the previous knowledge gathered from the project regarding measurements and the wants and needs of the demographic.

• Draw out basic forms onto yellow foam • Use the model shop to cut out the forms • Sand out imperfections • Prime, paint, and finish the bodies • Attach the cord and blades

Chapter 4 || Final Model Construction

63

Chapter 4 || Final Model

Final model In the end, a representation of the optimal hand mixers were created The end result illustrates a strong attention to the precise needs of the intended user. A close attention to detail shows careful consideration of the craftsmanship of the final models.

65

A round of applause A great number of people assisted the team while conducting this research project. This conclusive study would not have been possible without their guidance.

Chapter 4 || Acknowledgements

Professor Verena - For answering a million and one questions about anything and everything we ran into along the way.

IDUS 221 classmates - Who offered such constructive advice Mark (the shop guru) Leopold’s Ice Cream Parlor - For allowing us to research outside the shop.

The dozens of usability testers - Who were patient with us and eager to help.

73

Thank you.