The Benefits of Object-oriented Methodology for Software Development

International Journal of Information and Computer Science (IJICS) Volume 4, 2015 doi: 10.14355/ijics.2015.04.007

www.iji-cs.org

The Benefits of Object-oriented Methodology for Software Development Amos O Olagunju1, Bassey Akpan2 Computer Science and Information Technology, St. Cloud State University, USA

1

Division of Natural and Computational Sciences, Texas College, Tyler, USA

2

aoolagunju@stcloudstate.edu; 2bakpan@texascollege.edu

1

Abstract This research investigated the relationship between the object-oriented programming approach and software productivity at business organizations. Information systems executives at business organizations rated the quality of software products implemented with the object-oriented approach relative to those software realized with the structured and other traditional approaches. The executives also appraised the object-oriented approach in terms of its reusability strategy and the time for software development. This paper details the inferential data analysis of the use of the object-oriented approach in enhancing software productivity.

Keywords Object-oriented Approach; Structured Programming; Software Development; Reusability; Software Quality

Introduction The object-oriented approach is a code packaging tool that allows a designer to impose a reasonable structure on large software systems based on encapsulation and inheritance. Object-oriented programming provides several useful software development innovations. First, it provides a useful operational definition of module as a class.

Second, it establishes an organizing principle for task decomposition, and minimization of communication and dependencies among modules. Third, it enforces a useful formal separation between architecture, implementation, and realization. There is separation between public and private members of a class, and the separation of class declaration from class realization. Object-oriented design simplifies the structure of large software systems, just as years ago structured programming simplified the structure of code segments.

Object-oriented concepts are important in learning and understanding object-oriented technology. The key concepts are object, class, message, encapsulation, inheritance, and polymorphism. Object orientation technology refers to constructing programs from objects. An object is a combination of data (variables) and actions (methods).

Ideally an object is designed so that the data and the actions are closely related, rather than a random collection of entities and processes. Objects are central to object-oriented programming. A program is constructed from a collection of cooperating objects.

An object is a logical bundle of variables and methods. It is a self-contained module that can be easily used and understood. The principle of information hiding or encapsulation allows users to have restricted views of an object.

An object provides a set of services as public methods that can be shared. The object, its variables and the instructions that implement the methods are hidden from views. This enhances abstraction and modularity.

A class is a generalization of a set of objects. A programmer uses a class to declare the variables and methods of any of a set of objects. The type of a class can be private or public. The items of a private class can only be used within the class. The items in a public class can be referenced inside or outside the class. Creating an object is known as instantiating an instance of a class. A class is sometimes called an abstract data type. Classes allow programmers to construct new data types in addition to the built-in data types. The source code of an objectoriented program consists of a number of class descriptions. When a program runs, instances of the classes are invoked in an appropriate order to achieve the goal of the program [27].

39

www.iji-cs.org

International Journal of Information and Computer Science (IJICS) Volume 4, 2015

Encapsulation, inheritance and polymorphism are three basic concepts in object-oriented programming. These characteristics differentiate object-oriented programming from the traditional structured programming model.

Object-oriented programming builds on the concept of reusing code by allowing programmers to develop and maintain object libraries. These library objects are available for building and maintaining new applications.

Encapsulation is the process of combining related information and protecting it from the outside world. Programs consist of data and actions; in an object-oriented program these are appropriately grouped into an object to enable coping with software complexity. The information in an object can be hidden from view to avoid loading programmers with too much and thereby reducing complexity. Encapsulation involves the packaging of the data of an object with its methods or behaviors. Encapsulation allows the interface of an object to be separated from its implementation. The data and the implementation code of an object should be entirely hidden behind its interface [3]. Java provides some very powerful and secure encapsulation mechanisms. A package can encapsulate both classes and interfaces. A class definition can encapsulate attributes and methods. The public, package, protected and private access control modifiers can be used to control the visibilities and usability of attributes, methods and classes. The pubic modifier provides the broadest accessibility and the private modifier provides the tightest accessibility [1].

Abstraction in object-oriented programming is related to both encapsulation and data hiding [3]. A programmer can use abstraction to hide all but the relevant data of an object to reduce complexity and to increase efficiency.

Encapsulation prevents users from seeing the internal working of an object to protect data that should not be manipulated by the user. This makes the code more reliable and reusable [22]. Through inheritance new objects in a class can inherit the characteristics of the class. Polymorphism allows a single message to have different meanings to different objects. Object-oriented programming allows pieces of codes to be reused in constructing different software components.

Literature Review Object orientation has been anticipated as a feasible alternative to the traditional approaches in solving software development problems, in unbolting the way for high quality software enhancements, in promoting code reusability, in reducing software development risks, and in providing flexibility for software modifications [6, 15].

In deed object orientation can produce systems that are easily modified, extended, and maintained [4]. Object orientation ushers in new paradigms that require changes in mindset, and ways of thinking, representing and solving problems [6, 16, 20, 23, 24].

Researchers have contended that object orientation, as evolutionary approach, is only a refinement of some of the best software engineering ideas of the past[10, 12, 14, 17, 26, 29]. Although researchers [11, 18, 19, 33] have made efforts in the comparison of the object orientation approach to structured approach, no empirical investigations have tapped the opinions of information system managers who are engaged in the day-to-day activities of software development. Therefore, this study empirically examined the benefits of using the object-oriented approach over the traditional approaches to software development.

Object-oriented analysis and design indeed is an alternative approach to solveproblems in systems development [13]. Unlike both the classical and structured approaches that focus on the development process, object-oriented analysis and design methods emphasize the definition, structure, and use of data. The focus of the object-oriented approach is on objects, or data entities, and the set of methods that define meaningful operations on these objects.

The advantages of object-oriented approach include easier modeling that promote better user/analyst communication, the reusability of code, the improved flexibility in design, and the increased productivity and software reliability.

Object-oriented analysis and design techniques have already been successfully used for interfaces and computeraided design and engineering applications. Object-oriented methodologies in conjunction with formal description techniques have been viable in coping with the increasing complexity of embedded real-time systems [2]. Objectoriented development is also a partial-life-cycle method in which the decomposition of the network is based on the

40

International Journal of Information and Computer Science (IJICS) Volume 4, 2015

www.iji-cs.org

notion of an object [7]. Object-oriented method is different from the traditional functional approaches to design as it to help manage the complexity of massive software-intensive systems. The utmost strength of an object-oriented approach in software development is the mechanism it offers for capturing the real world model [5]. This enhances the maintainability and understandability of large systems. However, the basic constructs of objectoriented methods continue mature and converge in the analysis and design large systems [8].

The object methodologies are perceived as a strategy for the integration information systems. Large corporate organizations have continuously used object-oriented technologies in software development [9]. Object-oriented systems with adequate performance, reusable codes, ease of maintenance and modification have been successfully designed [30].Object-orientation provides the required transparency and consistency between the models of business and information technology systems. In fact object-oriented methods such as, the Banking Reengineering with Object-Oriented Modeling, have been adopted for redesigning banking business processes and information systems [21].

Changes in information technologies are evident in the realm of software development. Object-oriented analysis describes the actions of objects in a system designed to solve domains of a problem. Object-oriented design specifies the functions of the objects in a system. The class diagrams/templates, the object diagrams, and the object state diagrams that facilitate object-oriented analysis and design are documented in the literature [25]. Objectoriented methods reduce the risk inherent in the traditional waterfall approach to systems development, promote the reuse of existing codes, and reduce development time and cost [25]. The use of high quality reusable objects decreases the time required to develop software [28].

A survey showed a growing number of journals that covers object orientation. The Journal of Object-Oriented Programming is probably the best single-purpose journal [32]. There isan increase of interests in software architectures, and the role and nature of object-oriented analysis and its relationship to the process of requirements engineering. Object oriented offers long-term benefits of reduced development and maintenance costs, duplication, and time to develop software components. Object-oriented technology resolves the issue of reusability of both the data and process, and it helps to maintain the features of relational databases such as integrity, data sharing, and security.

Methodology An online Internet-based survey questionnaire was designed to solicit the opinions information systems managers on the benefits of the use of object-oriented methodology in software development. In the questionnaire the respondents rated (1) the extent to which object-oriented approach is used for software development relative to the structured and other traditional approach, (2) the degree to which object-oriented approach facilitates the reusability of codes relative to the structured approach, and (3) the magnitude of time saved in software development using the object-oriented approach. We assumed that information systems managers are too busy to respond hardcopy questionnaires and personal interviews. Consequently we emailed the link of survey instrument to managers in charge of software development at selected business organizations.

Limitations The heterogeneous nature of the sample of information systems executives used in this study is a threat to the validity of the results. The use of self-reporting method to obtain data about programming approaches to software development at specific organizations limits the generalization of the results. The variations in the budgets, revenues and sizes of organizations might confound the survey results. It is unclear if the perceptions of the sampled information systems executive are accurate and representative of their departments. The number of the information systems managers who responded to the survey was limited. This limitation could have biased the results because several knowledgeable information systems managers of software development might not have participated in the survey due to time constraints. This research targeted Fortune 1000 companies, a group not likely not to participate in this type of research.

41

www.iji-cs.org

International Journal of Information and Computer Science (IJICS) Volume 4, 2015

Research Procedures, Hypotheses and Data Analysis Participant organizations were systematically sampled from the directory of top computer organizations in the United States of America in the Fortune 1000 list. Every fifth organization in the list was selected and the survey was emailed to each of the top information systems manager in the sample. The survey instrument included a cover letter that explained the study and outlined the permission agreement. Postcard notes and email messages were sent every three weeks throughout the duration of the data collection phase, to remind the managers about the survey.

All returned questionnaires were reviewed for completeness. All surveys that failed to rate the utilization of objectoriented programming were purged from the data repository to maintain the integrity of the raw data. The specific null and alternative hypotheses studied are: H1o There is no statistically significant difference in the use of the object-oriented approach, structured approach, traditional approach and other approaches at any organization for the development of quality products.

H1a There is a difference in the use of at least two approaches by Information systems organizations for the development of quality products.

H2o There is no statistically significant difference in the reusability strategy of object-oriented approach and structured approach.

H2a Information systems organizations will tend to perceive more reusability strategy in the object-oriented approach than in the structured approach.

H3o There is no statistically difference in the perceived time saved to deliver products with the object-oriented approach.

H3a Information systems organizations will tend to perceive more time saved to deliver products with the use an object-oriented approach.

The Analysis of Variance (ANOVA) and Chi-square test were used to test hypothesis 1. The Chi-Square was used to test hypotheses 2 and 3. The Statistical Package for the Social Sciences (SPSS) was used to perform all data analyses. The level of significance for all tests was 0.05.

Results and Interpretation Manager and Organization Profiles Out of 1,000 surveys e-mailed, 200 surveys were returned due to incorrect e-mail addresses or were not delivered due to Spam. One hundred indicated they did not participate in such research surveys either because of time involved or object-oriented programming was not in their areas of expertise. Thus, a total of 700 organizations constituted the original sample pool. One hundred and eighty valid survey responses were returned; this accounts for the response rate of 25.7 percent.

The majority of the information systems executives had education beyond the undergraduate degree. Fifty-one respondents or 41.8 percent held an undergraduate degree, 41 respondents or 33.6 percent held a master degree, 23 respondents or 18.6 percent held a doctorate degree, and 7 respondents or 5.7 percent held other types of certificates.

The majority of the executives were vice presidents. Ten respondents or 7.8 percent held the position of VP of Technology Services; 4 respondents or 3.1 percent held the position of Director of Software Development; 50 respondents or 38.8 percent held the position of VP of Information Systems; 62 respondents or 48.1 percent held the position of VP of Software Development; and 3 respondents or 2.3percent held other positions.

The majority of the organizations where the executives worked had less than 500 employees. Twenty-six organizations or 21.5 percent had less than 50 employees; 33 organizations or 27.3 percent had between 51 to 100

42

International Journal of Information and Computer Science (IJICS) Volume 4, 2015

www.iji-cs.org

employees, 42 organizations or 34.7 percent had between 101 to 500 employees; 16 organizations or 13.2 percent had between 501 to 1,000 employees; 4 organizations or 3.3 percent had between 1,001 to 5,000 employees; and no organization had over 5,000 employees.

Benefit of Programming Approach on Product Quality Tables 1 and 2 contain the respective descriptive and inferential data for investigating the null hypothesis H1o.

Note that in Table 1, on a scale of 1 to 10, each information system executive rated the use of each programming approach on the quality of products. Clearly, more information systems managers rated the object-oriented approach than any other programming approach. The object-oriented approach received the highest average rating.

Table 2 presents the analysis of variance data for testing the null hypothesis H1o. The computed F value of 6.83 is larger than F = 2.609 with alpha = 0.05 and 3, 224 degrees of freedom. Consequently, we reject H1o in favor of H1a, and conclude that the quality of products depends on the approach to programming. The Scheffe’s method,

= ďż˝3 ∗ 2.609 ∗ 5.472 ∗ (1ďż˝đ?‘›đ?‘– + 1ďż˝đ?‘›đ?‘— )was used to compare pairs of means. The

ďż˝(đ?‘˜ − 1) ∗ đ??š3,224.0.05đ?‘€đ?‘†đ??¸âˆ— (1ďż˝đ?‘›đ?‘–+ 1ďż˝đ?‘›đ?‘—)

difference of 1.49 in the means between the use of object-oriented and structured programming approaches for quality product development is larger than the computed Scheffe’s test statistic of 1.135. Consequently, with five percent probability of committing a Type one error, information systems organizations tend to use the objectoriented more than structured programming approach for the development of quality products.

In order to further investigate the null hypothesis H1o, the managers from the sampled organizations were asked to indicate the programming approach currently in use. Table 3 shows the frequencies of the types or programming approaches in use at 178 organizations. The computed Chi-square of 25.33 is larger than Χ21, 0.05 =0.004.

Consequently, the proportion of organizations that used the object-oriented approach tends to be more than the proportion of organizations that applied the structured approach for product development.

TABLE 1: DESCRIPTIVE DATA OF QUALITY OF PRODUCT AND PROGRAMMING APPROACH

Object-Oriented

Structured

Traditional

Other

Total

N

108

48

36

38

228

Mean

6.49

5.00

6.22

4.97

5.88

Std. Deviation

2.248

2.634

2.356

2.175

2.428

5% lower Confidence Bound

6.06

4.24

5.43

4.25

5.56

5% Upper Confidence Bound

6.92

5.76

7.02

5.69

6.20

TABLE 2: ANOVA FOR QUALITY OF PRODUCT AND PROGRAMMING APPROACH

Sum of Squares

DF

Mean Squares

F

Sig.

6.830

.000

Between Groups

112.116

3

37.372

Within Groups

1225.686

224

5.472

Total

1337.803

227

TABLE 3: FREQUENCY OF APPROACH USED FOR PRODUCT DEVELOPMENT

Approach

Frequency

Expected Frequency

Object-Oriented

119

86

Structured

53

86

172

172

Total

X = 25.33, p-value < 0.005.

2

Benefit of Programming Approach on Code Reusability Table 4 displays the frequency, percentage and expected frequency of information systems manager who rated the object-oriented approach as enhancing the reusability of codes more than the structured-oriented approach. Note that the â&#x20AC;&#x153;disagreeâ&#x20AC;? and â&#x20AC;&#x153;strongly disagreeâ&#x20AC;? were omitted from the computation of the Chi-Square because the

43

www.iji-cs.org

International Journal of Information and Computer Science (IJICS) Volume 4, 2015

frequency was zero. The computed Χ12=4.625 with the “strongly agree, agree and neutral” cells, and Χ22=22.53 with “strongly agree, and agree” cells collapsed versus the “neutral” cell. The 86 percent of the information systems managers who at least agreed that object-oriented approach enhances the reusability of codes is statistically significant at the 0.05 level.

TABLE 4: REUSABILITY ENHANCEMENT OF OBJECT-ORIENTED OVER STRUCTURED APPROACH

Rating

Frequency

Percentage

Expected Frequency

Strongly Agree

33

27.50

40

Agree

53

44.17

40

Neutral

34

28.33

40

Disagree

0

0.00

*

Strongly Disagree

0

0.00

*

Total

120 Χ1

22, 0.05

=0.352, Χ1 =4.625; Χ2 2

100 21, 0.05

=0.004, Χ22=22.53

Benefit of Object-Oriented Approach on Time Saving Table 5 contains the ratings of the information systems managers who indicated that the use object-oriented programming saved time in delivering products to customers. The proportions of managers who at least agreed that object-oriented promoted faster product delivery to customers was 0.825. This 82.5 percent is significant at the 0.05 level. Consequently, the majority of managers acknowledged that object-oriented programming allowed organizations to respond to customers within a time frame.

TABLE 5: TIME SAVING APPROACH OF OBJECT-ORIENTED APPROACH

Rating

Frequency

Percentage

Strongly Agree (1)

34

28.33

Expected Frequency

Agree (2)

65; (1)+(2)=99

54.17

Neutral (3)

19

15.83

60

Disagree (4)

2; (3)+(4)=21

1.67

60

Strongly Disagree

0

0.00

*

Total

120

100

Χ21, 0.05 =0.004, Χ2=50.7

Conclusions The survey response rate of below 30 percent in this research is low. However, the response rates to the surveys of senior executives are typically low [31]. This response rate is actually quite good, given that senior company executives were required to address the benefits of software development [31].

The Object-Oriented approach involves encapsulating data and code. In the Object-Oriented approach all systems applications are viewed as a collection of interlocking objects that allow organizations and end users to easily understand logical entities. In fact the greatest strength of the object-oriented approach to software development is the mechanism it offers for modeling the real world [7]. This enhances the ability to maintain and understand the components of software systems.

Object-oriented approach provides the benefits of the reuse of codes and saves the time for developing quality products. The business organizations ought to adopt object-oriented methodologies in the development of future information systems.

REFERENCES

[1]

Adams, J., Nyhoff, A. J. &Nyhoff, J. (2001), “Java: An Introduction to Computing”, Prentice Hall, Inc.

[2] Alvarez, J. M., Diaz, M.&Llopis, L. (2003), “An Object-oriented methodology for embedded real-time systems”, The

44

International Journal of Information and Computer Science (IJICS) Volume 4, 2015

www.iji-cs.org

Computer Journal, 46(2), 123-145.

[3] Bell, D. & Parr, M. (2002), “Java for Students”, (3 ed.), Prentice Hall, Inc. [4]

Berard, E. V. (1993), “Essays on object-oriented software engineering”, Prentice Hall, Inc.

[5]

Booch, G. (1986), “Object-oriented development”, IEEE Transactions on Software Engineering, SE-12(2), 211-221.

[6]

Booch, G. (1991), “Object-Oriented Design with Applications”, Benjamin Cummings Publishing Company, Inc.

[7]

Booch, G., (1994), “Object-Oriented Analysis and Design with Applications”, Addison-Wesley.

[8]

Bowles, A. (May 1995), “Object methods emerging and converging”, Software Magazine, 15(5), 2.

[9]

Bucken, M. (1993), “OO methods vie for recognition”, Software Magazine, 13(7), 2.

[10] Cargill, C. (1995), “Understanding the rules of OT”, Uniform Monthly, 15(1).44-45.

[11] Culnan, J. M. (1987), “Mapping the intellectual structure of MIS, 1980-1985: A co-citation analysis”, MIS Quarterly, 341-350.

[12] Due, R. T. (1993), “Object-oriented technology: The economics of a new paradigm”, Information Systems Management, 6974.

[13] Garceau, L. R., Jancura, E. G. &Kneiss, J. (1993), “Object-oriented analysis and design: A new approach to systems development”, Journal of Systems Management, 44(1), 8.

[14] Henderson-Sellers, B. & Constantine, L. L. (1991), “Object-oriented development and functional decomposition”, Journal of Object-Oriented Programming-Focus on Analysis and Design, 18-23.

[15] Korson, T. & McGregor, D. J. (1990), “Understanding object-oriented: A unifying paradigm”, Communications of the ACM, 33, 9, 40-60.

[16] Li, X. (1991), “Integration of structured and object-oriented programming”, Journal of Object-Oriented ProgrammingFocus on Analysis and Design, 54-60.

[17] Lilly, S. (1993), “The structure of software revolutions (and the difficulty of teaching them”, Object Magazine, 3(3), 77-79.

[18] McCain, K. W. (1984), “Longitudinal author cocitation mapping: The changing structure of macroeconomics”, Journal of the American Society for Information Science, 35, 351-359.

[19] McCain, K. (1990), “Mapping authors in intellectual space: A technical overview”, Journal of the American Society for Information Science, 41.

[20] Meli, M. (1994), “Object orientation-real or hype?”, Data Management Review, 4(7), 24-26.

[21] Mentzas, G. N. (1997), “Re-engineering banking with object-oriented models: Towards customer information systems”, International Journal of Information Management, 17, 179-197.

[22] Orr, J. N., (1992), “What's the big deal about objects?”, Computer - Aided Engineering, 11, 11.

[23] Page-Jones, M. & Weiss, S. (1991), “Synthesis: An object-oriented analysis and design method”, Journal of Object-Oriented Programming - Focus on Analysis and Design, 133-135.

[24] Parodi, J. (1995), “Distributed object technology: The long view”, Uniforum Monthly, 15(1), 34-36.

[25] Pei, D. &Cutone, C. (1995), “Object-oriented analysis and design”, Information Systems Management, 12(1), 54.

[26] Pun, W. & Winder, R. (1991), “Design method for object-oriented programming”, Journal of Object-Oriented Programming-Focus on Analysis and Design, 61-73.

[27] Render, H., (1996), “Object-Oriented Analysis and Design: Using the Object Modeling Technique (OMT)”, MCI Communications Corporation, Colorado Springs, CO. [28] Sanchez, N. G. &Choobineh, J. (1997), “Achieving reuse with OO technology”, Information

Systems Management,

14(2), 48-55.

[29] Sarna, D. &Febish, G. (1995), “Think objects? Think big”, Datamation, 25-27.

[30] Smith, C. U. & Williams, L. G. (Nov 1997), “Performance engineering of object-oriented systems”, Capacity Management Review, 25 (11), p. 1-18 (17 pp.).

[31] Venkatraman, N. (1989), “Strategic orientation of business enterprises: The construct, dimensionality, and measurement”,

45

www.iji-cs.org

International Journal of Information and Computer Science (IJICS) Volume 4, 2015

Management Science, 35, 942-962.

[32] Webster, S. (1994), “An annotated bibliography for object-oriented analysis and design”, Information and Software Technology, 36(9), 569.

[33] White, D. H. & Griffith, C. B. (1981), “Author cocitation: A literature measure of intellectual structure”, Journal of the American Society for Information Science, (32), 163171.

Amos O Olagunju is a professor in the Department of Computer Science and Information Technology at St. Cloud State University (SCSU) in Minnesota. He previously served as the interim dean of undergraduate studies for two years at SCSU. Prior to that position, he served as the dean of the School of Graduate Studies and chief research officer at Winston Salem State University in North Carolina. Amos served as the chair of the Mathematics and Computer Science Department, and later the Computing and Information Sciences Department, at Delaware State University (Dover, DE). Before that, he taught in the Asian Division at the University of Maryland University College, North Carolina A&T State University, and Michigan State University. A faculty fellow and later a senior faculty fellow selected jointly by the American Society of Engineering Education and the Navy, Amos developed manpower mobilization and data-mining algorithms for monitoring the retention behaviors of personnel. As a member of the technical staff at Bell Communications Research (now Telcordia), he developed an architecture for a generalized C transaction environment, quantitative models for system workload projection and characterization, software metrics, and managerial decision support systems. As Carnegie African Diaspora fellow, he recently helped Caleb University in Nigeria to develop graduate programs in Computer Science. He is a senior member of the ACM. His current research interests are in the areas of bioinformatics, quantitative security risk assessments, cryptography, numerical computing, and artistic storytelling of breakthrough computing algorithms and technologies.

BasseyAkpan is a professor and chair of the Division of Natural and Computational Sciences at Texas College located at Tyler, Texas, USA. He received Doctor’s Degree in Information System at Argosy University, USA in 2005. His research area is in computer security, database, and computer human interaction.

46