A Proposed Hybrid Web Engineering Process Model for Large-Scale Web-Based Applications Development in Large Web Development Enterprises

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A Proposed Hybrid Web Engineering Process Model

for Large-Scale Web-Based Applications

Development in Large Web Development Enterprises

Submitted By

Omaima Nazar Ahmad AL-Allaf

Supervised By

Prof. Dr. Asim El-Sheikh

Dissertation

Submitted in Partial Fulfillment

of the Requirements for the Degree of

Doctor of Philosophy

In

Computer Information Systems

Faculty of Information Systems and Technology

The Arab Academy for Banking and Financial Sciences

Amman-Jordan

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AUTHORIZATION

I, the undersigned

Omaima Nazar Ahmad Al-Allaf

authorize the Arab Academy for

Banking and Financial Sciences to provide copies of this Dissertation to Libraries,

Institutions, Agencies and any Parties upon their request.

Name:

Omaima Nazar Ahmad Al-Allaf

Signature:

Date: 12/8/2008

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DEDICATION

All respect and very special appreciation to my Dear mother “Doctor.Nida’a

Hazem” for her encouraging and supporting to me

And also to my lovely daughter “Dalia” for her encouraging and patience to me

With Respect…………

Omaima Al-Allaf

12 August 2008

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ACKNOWLEDGEMENTS

I would like to thank God, first and foremost, for having guided me through the

critical stages of my life to successful completion.

This thesis is the result of almost four years of full-time study, and during this time

I have been supported by many people. I am delighted to now have the opportunity

to express my sincere gratitude and appreciation to all of them.

I am deeply indebted to my supervisor, Professor Asim Elsheikh for his stimulating

suggestions, guiding hand and expertise in the field of Software Engineering.

Special thanks also due to the staff members of the Department of information

Systems- The Arab Academy for Banking and Financial Sciences-Amman-Jordan

for their constant cooperation and help during this period of research.

I would like to extend my deepest gratitude and sincere thanks to my mother for her

affectionate support that has acted as a necessary stimulus to my academic quest.

Finally, my thanks go to my daughter DALIA has helped me to achieve my goal

through her patience, understanding and willingness to accommodate my dream.

Omaima Al-Allaf

12 August 2008

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Published Papers

Omaima N. Al-Allaf, Guidelines for Using Multimedia in Webpage and User Interface

Design, Proceedings of the 4th International Multiconference on Computer Science and

Information Technology (CSIT2006), ASU (private), Vol.3, pp.568-577, Amman, Jordan, 5-7 April 2006.

Omaima Nazar Ahmad AL-Allaf and Asim El-Sheikh, Guidelines for Constructing Web

Engineering Process Models for Developing Large-Scale Web-Based Applications,

The 1st international conference on digital communications and computer applications (DCCA 2007), Jordan University of Science & Technology, pp.651-666, Irbid, Jordan, 19-22 March 2007.

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ABSTRACT

Currently, the level of adoption of current practice and software process improvement (SPI) in large enterprises is unknown. A literature and a practical survey of web development methodologies has been conducted in this thesis to identify web engineering practice and to understand the extent of web practices currently in use in large enterprises to help improving the software processes. This survey clarified that, there were several web methodologies that has concentrated on delivering functional web applications but most of these applications run over time and budget and without consideration on SPI and quality requirements. The survey confirmed also that the: tools and technology, and standards and procedures are partially adopted, whereas, the project management planning, customer involvement practices, web metrics, and the control of the development process are barely used by these enterprises.

A Hybrid web engineering process model for developing the large web applications in large enterprises has been proposed in this thesis. This model consists of many activities to follow: possible division of large web application into many small sub applications; possible division of large number of developers into many sub teams; identify a management team to control and monitor the development process; Stakeholders’ and customers’ inclusion and feedback during web development process; requirement analysis, management and development; risk analysis of all large web application’s components; adopting the Spiral model by management team to manage and monitor the development progress; adopting the Throwaway Prototype model by each sub team for requirements gathering; adopting the XP agile method by each sub team for customer communication during the development process; adopting WebEng process model by each sub team to match web application’s properties and challenges; adopting a suitable user interface design approach; conducting CMMI levels key process areas; conducting web engineering practices; integrating SQA activities; and training the mmanagers and developers on CMMI and web engineering practices. This model is focuses on overall development process phases such as: requirement gathering and analysis; cost, time and effort estimation; planning; design; coding; testing, verification and validation; integration; and documentation.

According to Hybrid model evaluation with CMMI levels key process areas, we investigate that: This model steps covered and largely satisfied both of CMMI Level2 and CMMI Level3 process areas; whereas, satisfied CMMI Level4 process areas; but partially satisfied CMMI Level5 process areas. According to Hybrid model comparison with XP, Spiral and WebEng in

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their compatibilities with CMMI levels process areas; we investigate that this model can overcome the limitations of these process models to use them in combinations. Finally, the evaluation of the Hybrid model according to CMMI process areas has been conducted in this research. This evaluation has been carried out by the aiding of many professional developers and managers currently working in many large web-development Jordanian enterprises. The evaluation results shows that the Hybrid model satisfied about 85.57% of CMMI level2, 86.86% of CMMI level3, 73.35% of CMMI level4, and finally about only 31.65% of CMMI level5.

The study indicates that large enterprises can benefit from Hybrid model if they apply it in good manner with sufficient training because it was being noted from the analysis of Hybrid steps that: this model can overcome as possible as the problems of large web applications development mentioned in the literature researches and also web development problems in these large web enterprises.

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List of Tables

Table Name Page

Table (2.1): Traditional versus Agile Software Development……… 33

Table (2.2): The Summary of Risk-Based Method ……… 35

Table (2.3): The Core RE Activities ……… 39

Table (2.4): Estimation Dimensions and Corresponding Project Factors………. 44

Table (3.1): The Factors Affecting Organizational Change in SPI Efforts……… 59

Table (3.2): The Fundamentals of Software Development in Plan-Driven and Agile……… 61

Table (3.3): The Quality Attributes of Web-Based Applications………. 65

Table (4.1): Factors Used by Enterprises to Measure the Size of Web Applications……… 72

Table (4.2): Descriptive Statistics of the Current Position of Employee……… 75

Table (4.3): The Descriptive Statistics of Respondents’ Current Work Activities……… 76

Table (4.4): Descriptive Statistics of Developers Receiving any CMMI Training ………... 76

Table (4.5): Descriptive Statistics of Respondents’ Participated in Forms of SPA ……… 77

Table (4.6): Descriptive Statistics of Developers’ Experience in Present Organization ……… 77

Table (4.7): Descriptive Statistics of Overall Software Experience of Developers ……… 78

Table (4.8): Descriptive Statistics of Level of Experience with Web Development ………... 78

Table (4.9): Descriptive Statistics of Different Sizes of Large Jordanian Enterprises ……… 79

Table (4.10): Descriptive Statistics of Application Domain in Jordanian Enterprises ………... 79

Table (4.11): Describe If Development Involve In-House, Outsource or Reusability ……… 80

Table (4.12): Statistics of Developers’ Familiarity with Development Methodologies ……… 81

Table (4.13): Descriptive Statistics of Development Methods Used by Enterprises……… 82

Table (4.14): Descriptive Statistics of Test Types Required by Organization ……… 82

Table (4.15): Descriptive Statistics of Performed Assurance Activities ……… 83

Table (4.16): Frequent Distribution of Who Performed Assurance Activities ……… 84

Table (4.17): Developers’ Perceptions Toward Symptoms at Organization ……… 85

Table (4.18): The Statistics of Organizational Issues in Web Engineering Practices ……….. 88

Table (4.19): Statistics of Standards and Procedures in Web Eng Practices ……… 90

Table (4.20): The Frequency Distribution of Web Metrics in Web Engineering Practices ……….. 92

Table (4.21): The Frequency Distribution of Control of the Development Process ……….. 94

Table (4.22): The Frequent Distribution of Tools and Technology in Web Eng Practices ……… 95

Table (5.1): Problems in the Literature ……… 102

Table (5.2): Problems of Large Web Development in Large Jordanian Enterprises ……… 102

Table (5.3): Problems of Web Engineering Practices in Large Jordanian Enterprises ……… 102

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Table Name Page

Table (5.5): Problems in the Literature solved by the Hybrid model ……….. 131

Table (6.1): Hybrid Activities Against the Activities of CMMI Level2 ………. 135

Table (6.2): Hybrid Activities Against the Activities of CMMI Level3 ……….. 137

Table (6.3): Hybrid Activities Against the Activities of CMMI Level4 ……… 141

Table (6.4): Hybrid Activities Against the Activities of CMMI Level5 ……… 141

Table (6.5): Coverage of CMMI-Level2 Areas by XP, Spiral, WebEng and Hybrid ……….... 143

Table (6.6): Coverage of CMMI-Level3 Areas by XP, Spiral, WebEng and Hybrid ………. 144

Table (6.7): Coverage of CMMI-Level4 Process Areas by XP, Spiral, WebEng and Hybrid ………… 146

Table (6.8): Coverage of CMMI-Level5 Process Areas by XP, Spiral, WebEng. and Hybrid ……….. 146

Table (6.9): Coverage of CMMI Generic Practices by XP, Spiral, WebEng and Hybrid ……… 147

Table (6.10): The Results of CMMI level2 Requirements Management ……… 149

Table (6.11): The Results of CMMI level2 Project Planning ……….. 150

Table (6.12): The Results of CMMI level2 Project Monitoring and Control ………... 150

Table (6.13): The Results of CMMI level2 Supplier Agreement Management ……… 151

Table (6.14): The Results of CMMI level2 Measurement and analysis ……….. 152

Table (6.15): The Results of CMMI level2 Process and Product Quality Assurance ………. 152

Table (6.16): The Results of CMMI level2 Configuration Management ……… 153

Table (6.17): The Results of CMMI level3 Requirements Development ……… 154

Table (6.18): The Results of CMMI level3 Technical solution ……….. 154

Table (6.19): The Results of CMMI level3 Product Integration ………... 155

Table (6.20): The Results of CMMI level3 Verification ………. 156

Table (6.21): The Results of CMMI level3 Validation ……… 156

Table (6.22): The Results of CMMI level3 Organizational Process Focus ………. 157

Table (6.23): The Results of CMMI level3 Organizational Process Definition ……….. 157

Table (6.24): The Results of CMMI level3 Organizational Training ………... 158

Table (6.25): The Results of CMMI level3 Integrated Project Management ………... 159

Table (6.26): The Results of CMMI level3 Risk Management ……….. 159

Table (6.27): The Results of CMMI level3 Decision Analysis and resolution ……… 160

Table (6.28): The Results of CMMI level4 (2 Process Areas) ……… 161

Table (6.29): The Results of CMMI level5 (2 Process Areas) ……… 161

Table (6.30): The Summary of Hybrid Model Evaluation by CMMI ………. 162

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List of Figures

Figure Name Page

Figure (1.1): The Framework of Web Engineering Process ……… 4

Figure (1.2): The Research Methodology………. 15

Figure (1.3): The Outlines of the Thesis ……….……… 17

Figure (2.1): The Web Engineering – A multidisciplinary field……….. 20

Figure (2.2): Complementary and Conflicting Goals in a Software project ………. 23

Figure (2.3): The Throwaway Prototype……….. 26

Figure (2.4): The Spiral Software Process Model ……… 27

Figure (2.5): The Rational Unified Process……….. 28

Figure (2.6): The Life Cycle of the XP Process ……….. 30

Figure (2.7): The General Process for User Requirements Analysis ……….. 40

Figure (2.8): The Model-Driven Approach for Web Systems ……… 42

Figure (2.9): A More Detailed Model for a Web Application, Showing User Roles and Interactions… 47 Figure (3.1): The Staged View of CMMI ……… 53

Figure (3.2): Agile Adoption and Improvement Model ……….. 62

Figure (4.1): Factors Used by Enterprises to Measure the Size of Web Applications ……… 72

Figure (4.2): Relationships between Teams in Enterprises ………. 74

Figure (4.3): Describe the Frequencies of Current Position of Employee ……… 75

Figure (4.4): The Frequencies of Respondents’ Current Work Activities ……… 76

Figure (4.5): The Frequencies of Developers Receiving Any CMMI Training ………. 76

Figure (4.6): Participation in Software Process Improvement ………. 77

Figure (4.7): Frequencies of Developers’ Experience in Present Organization ……….. 77

Figure (4.8): Frequencies of Overall Experience of Developers ……… 78

Figure (4.9): Frequencies of Level of Experience with Web Development ……… 78

Figure (4.10): Frequencies of Different Sizes of Large Jordanian Enterprises ………... 79

Figure (4.11): Frequency Distribution of Application Domain ……….. 80

Figure (4.12): Describe If Development Involve In-House, Outsource or Reuse ……… 80

Figure (4.13): Frequencies of Development Methods Which developers Familiar With ……… 81

Figure (4.14):Frequencies of Development Methods Used by Enterprises ………... 82

Figure (4.15): Frequency distribution of Test Types Required by Organization ……… 83

Figure (4.16): Frequent Distribution of Performed Assurance Activities ……… 83

Figure (4.17): Frequent Distribution of Who Performed Assurance Activities ……….. 84

Figure (4.18): The Mean of Severity Score Description of All Symptoms ……… 86

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Figure (4.20): Organizational Issues in Web Engineering Practices ………... 89

Figure Name Page Figure (4.21): Standards and Procedures in Web Engineering Practices ……… 91

Figure (4.22): Web Metrics in Web Engineering Practices ……… 93

Figure (4.23): Control of the Development Process in Web Engineering Practices ………... 94

Figure (4.24): Tools and Technology in Web Engineering Practices ………. 96

Figure (4.25): Overall Best Practices Adoption in Large Jordanian Enterprises ………. 99

Figure (5.1): The Proposed Guidelines for Constructing Web Eng Process Models ……….. 104

Figure (5.2): Web-Based Application Division ……….. 104

Figure (5.3): The Complete Hybrid Web Engineering Process Model ………... 107

Figure (5.4): The Interaction Process between the Management and Sub Team ………... 108

Figure (5.5): The Integration of Web Engineering Process with XP Practices ………... 109

Figure (5.6): Relationships between teams in enterprises ……… 116

Figure (5.7): Steps of UI design of Sub Web Application ……… 119

Figure (6.1): The Results of CMMI level2 Requirements Management ………. 149

Figure (6.2): The Results of CMMI level2 Project Planning ……….. 150

Figure (6.3): The Results of CMMI level2 Project Monitoring and Control ……….. 151

Figure (6.4): The Results of CMMI level2 Supplier Agreement Management ……… 151

Figure (6.5): The Results of CMMI level2 Measurement and Analysis ………. 152

Figure (6.6): The Results of CMMI level2 Process and Product Quality Assurance ……….. 152

Figure (6.7): The Results of CMMI level2 Configuration Management ………. 153

Figure (6.8): The Results of CMMI level3 Requirements Development ……… 153

Figure (6.9): The Results of CMMI level3 Technical Solution ……….. 155

Figure (6.10): The Results of CMMI level3 Product Integration ……… 155

Figure (6.11): The Results of CMMI level3 Verification ……… 156

Figure (6.12): The Results of CMMI level3 Validation ………... 156

Figure (6.13): The Results of CMMI level3 Organizational Process Focus ……… 157

Figure (6.14): The Results of CMMI level3 Organizational Process Definition ………. 158

Figure (6.15): The Results of CMMI level3 Organizational Training ………. 158

Figure (6.16): The Results of CMMI level3 Integrated Project Management ………. 159

Figure (6.17): The Results of CMMI level3 Risk Management ………... 160

Figure (6.18): The Results of CMMI level3 Decision Analysis and Resolution ………. 160

Figure (6.19): The Results of CMMI level4 (2 Process Areas) ……….. 161

Figure (6.20): The Results of CMMI level5 (2 Process Areas) ……….. 161

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List of Abbreviation

Abbreviation of the study’s constructs

Hybrid ……… Hybrid Web Engineering Process Model

WebEng ………. Web Engineering Process Model

XP ………... Extreme Programming QA ……….. Quality Assurance

SQA ……… Software Quality Assurance SPI ……….. Software Process Improvement

CMM ………. Capability Maturity Model

CMMI ………. Capability Maturity Model Integration SEI ……….. Software Engineering Institute

KPA’s ………. Key Process Areas

SBPQ ………. Software Best Practice Questionnaire

DB ……….. Data Base

ASP ……… Agile Software Development Process

OO ………. Object Oriented

OOP ……… Object Oriented Programming

RUP ………... Rational Unified Process

RE ……….. Requirements Engineering

ISO ………. International Organization for Standardization

UI ………... User Interface

UID ………. User Interface Design

SCM ………... Software Configuration Management

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Chapter 1 Overview of the Thesis

1.1 Introduction

During the last decades, the web-based applications are evolving rapidly using many new technologies, programming languages and models that are being used to increase the interactivity and usability of these applications. A web-based application is a software system based on technologies and standards of the World Wide Web Consortium (W3C) that provides web resources such as content and services through a user interface and web browser [1]. The web-based applications have the properties of network intensiveness, concurrency, unpredictable load, performance, availability, data driven, content sensitive, continuous evolution, immediacy and security [2].

Web engineering is concerned with the use of scientific, hypertext engineering, software engineering best practices, advances, management principles, disciplined, systematic methodologies, iterative process, better development tools and a set of good guidelines to the successful development, deployment, performance evaluation and maintenance of high quality web sites and web-based applications [3]. The emerging field of web engineering aims to bring the web application’s development under control, minimizes risks, enhances web site maintainability, quality and successfully manages the diversity and complexity of web application’s development to avoid major failures of web applications’ development [4]. The complexity of designing, developing, maintaining and managing web applications have increased significantly when web applications have evolved [4].

The objective of this chapter is to give a brief description of web-based application, web engineering, development process of web-based applications and large web applications. This chapter includes the importance of this research, problems in developing large-scale web applications and research objectives. This chapter also includes literature review, literatures related to development methodologies of web applications, literatures related to development methodologies of large web applications and analysis of these literatures. Finally, this chapter includes research methodology and outline of this thesis.

1.2 The Development Process of Web-Based Applications

The development of modern web-based applications requires a methodologically sound engineering approach because these web applications are complex software systems. The web engineering comprises the use of systematic and quantifiable approaches based on software

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engineering in order to accomplish the specification, implementation, operation and maintenance of high-quality web applications [1].

The web site’s structure, functionality and information contained within it may evolve and change continuously over time to keep information current and to meet user requirements. So it is not possible to specify fully what a web site should contain at the start of the development process. Therefore, the ability to maintain information, scale the structure and functions of web site are major factors that make web application development different in comparison to traditional software development. These factors should be taken into consideration when developing web applications [5].

Many of new methodologies related to web development focused on the user interface design but failed to address the wider aspects, complexity and overall development process of web-based applications [6]. At the same time, the traditional software process models of traditional information systems have challenges to accommodate web specific aspects into their techniques and practices. Therefore, the development of web-based applications requires a mix of web site development techniques together with properties of traditional software process models [7].

1.3 The Large-Scale Web-Based Applications

The simplest form of web applications consists of a set of linked hypertext files that present information using text and limited graphics. When the importance of e-business applications grow, the web applications are evolving into sophisticated computing environments that provide standalone features, computing functions, content to the end user and are integrated with corporate databases and business applications [2]. The properties of large web applications are defined in few literature researches. Garland and Anthony [8] defined a large software project as a system that: including large quantities of source code typically millions of lines; including large number of developers (more than 50, often geographically distributed); including large number of interactive functions; using of multiple programming languages; using multiple mechanisms (files, relational and object databases); and distributing the components over several hardware platforms. Whereas, Bell [9] defined the large-scale software as a system that: comprising a large number of interactive activities that carried out by large number of developers (at least 50) working over lengthy time spans. While, Curtis, et. al. [10] defined the large-scale software project as a system that: involving at least 10 people; involving real-time, distributed or embedded applications; and including hundreds of thousands of lines of delivered system source code.

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On the other hand Burstin and Ben-Bassat [11] defined the large software as a system that having large and diverse community of users, organizational and interactive activities; including hundreds of thousands of lines of code; including hundreds to thousands pages of documentation; requiring long development time; consuming very large resources during the development and maintenance phases. Whereas Tamai and Itou [12] defined the large-software project as a system that: is large in program size, investment cost and development period; consisting of large collections of data; and integrating huge number of interacted functions.

And Barnett [13] defined large-scale software project as a system that: involving developers from different companies and cultures; comprising teams with 50 or more members; integrating with legacy applications and third-party software packages; and including a number of sub-project teams that integrate their sub-systems to build the final application. Finally, Delic and Dayal [14] defined large-scale software as a system that: is heterogeneous and very dynamic; involving complex interactive activities among many humans, applications, services and devices; including hundreds of thousands of strategic decisions to operational decisions are made on each business day within the large enterprises.

1.4 The Importance of this Research

The large-scale web application consists of large number of interactive web pages and functions that supports multiple users who access these functions through internet and connected networks. The development of based applications especially large-scale web-based applications has become common because of the growth of the internet and networks. Therefore, successfully developing large-scale web applications that will execute correctly and consistently in a distributed environment where hundreds or millions of requests need to be serviced is a very difficult task.

The development methodologies of web-based applications are still in their early stages and new technologies continue to discover. Sometimes these technologies are alternatives and other times they are used in combinations. Balakrishnan and Somasundaram [15] addressed the key requirements for the successful development of large projects such as: user involvement; management support; clear statement of requirements and the ability to verify them; and proper planning [15]. On the other hand, McDonald and Welland [16] suggested that there is a need to focus on many factors to achieve the success of web applications’ development such as: more requirements analysis; clear analysis of business needs; better

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testing and evaluation of web deliverables; and more focus on the issues associated with the evolution of web applications [16]. There is no uniform approach exists to web applications’ development. Therefore, the web developers need new techniques and guidelines that capture requirements and integrate them within a systems development methodology [17].

The WebEng is a web engineering process model that developed by Pressman [2]. The WebEng consists of many steps as shown in figure (1.1). Pressman focused in this model on the development of web-based applications in general and did not consider the size of these web applications. After that, many researches worked to create high quality web-based applications that deliver a set of complex content and functionality to a broad population of end users. Bahli and Tullio [18] mapped and discussed in their research the progress made so far on web engineering development. They summarized and classified the literature empirical studies on web engineering based on the six phases of the Pressman web engineering process model. They found that much of the web engineering researches focused on the engineering activity. Almost 70% of the published researches concerned with the engineering part of web applications’ development process such as architectural design, navigation design and interface design tasks of engineering activity and customer evaluation seem to draw more research. Their results suggested a significant need for theory-based research in web engineering.

Figure (1.1): The Framework of Web Engineering Process [2]

According to as listed above, the importance of this research is to propose a web engineering process model that we hope to be more suitable for successful development of large web applications and deliver these applications within the time, budget and effort.

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1.5 The Problems in Developing Large-Scale Web-Based Applications

Many organizations failed to develop large and high-performance web applications. There are many literature researches which addressed the factors responsible for the failure of web applications and highlights serious problems that affecting the large web applications’ development. The most important problems that caused the failure of development of large web applications are as follows:

1. Problems in requirement analysis phase [16].

2. Poor project management of development process [16]. 3. Poor project estimation [16].

4. The development of web applications that exceeds the budget [19]. 5. Flawed design and development process [20].

6. Poor understanding of methodology to develop large web-based applications [20].

1.6 The Research Objectives

The objectives of this research are as follows:

1. Proposing a web engineering process model for the development of large-scale web-based applications. We will build this model according to the modification and combination of the basic properties of well known traditional software, agile and web engineering process models.

2. Focusing on the overall development process of large web applications because most of the other earlier researches and methodologies focused only on one development phase such as design, requirements, etc.

3. Reaching a suitable methodology that achieve as possible as an effective development of large web applications and reducing the likelihood of failure of these applications. We will focus in the proposed web engineering model to overcome as possible as the most problems of large web applications’ development and deliver large web applications on time, effort and within budget. The research questions are:

Q.1: Is the proposed web engineering process model compatible with the Software Process Improvement (SPI) Capability Maturity Model Integration (CMMI) key process areas and goals (KPA’s) to improve the web development process of the large enterprises and their software quality assurance (SQA)?

Q.2: Can the adopting of this proposed web engineering process model overcome as possible as the limitations and challenges of traditional software process models and agile methodologies?

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Q.3: Can the adopting of this proposed web engineering process model overcome as possible as the development problems of large web applications mentioned in literature researches and studies?

Q.4: Can the adopting of this proposed web engineering process model in large enterprises for the development of large web applications within budget, effort and time and overcome as possible as the web development problems?

4. Analyzing the compatibility of the proposed model according to CMMI KPA’s to determine the advantages properties of this model against other development models. 5. Finally, the objective also is to evaluate this model (according to CMMI levels) by many

professional developers and managers currently working in many large Jordanian enterprises which undertaken large web development. The objective of this evaluation is to determine which CMMI level can be reached by these enterprises when adopting this proposed model.

1.7 Literature Review

Many software process models and approaches for web applications’ development had been studied and proposed in the literature. Until now there are few studies about proposing web process models for developing large web applications. However, there is much room for improving existing models and approaches or coming up with new effective web models for the development of large web applications. We divided the literature review into two sections: development methodologies for web applications and the development methodologies for large web applications.

1.7.1 Literatures Related to Development Methodologies of Web Applications

This section includes the literatures related to web engineering process methodologies and techniques for developing web applications without mention to the size of these web

applications. A summary and analysis of these literatures are given below:

Kushwaha, et. al. [20] addressed the factors that responsible for failure of web

applications. They focused on user-centric approach of requirement engineering to help increasing the success rate of web applications’ development. They proposed the major activities that should be part of a web application’s development in order to improve the reliability of web applications. They proposed cognitive process of socio-psychological requirement engineering to overcome the blurring between the requirement engineering and analysis, and also to adopt a more comprehensive approach before cognitive requirement

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engineering is carried out. They highlighted fifteen complexity issues that have a major effect on the successful development of web applications.

Hsieh [21] presented a development methodology for web applications that serves as a

road map to guide web development. This methodology consists of three phases: structural design, detailed design and implementation. Structural design views a system at the web-page level and detailed design deals with issues of intra-page. The implementation is logically segmented into four steps: implementation of the visual interface, client-side scripting, sever-side scripting for the visible interface, and server-sever-side scripting for pages and tasks without a visual interface.

Souza and Falbo [22] presented an agile approach for development of web applications

which used the concept of agile modeling. They started web engineering process with the identification of business needs, followed by project planning. Next, requirements are detailed and modeled, analysis and design. Then the application is built using tools specialized for the web applications. Finally, the system is tested and delivered to end users. Their approach included four activities: requirement specification, analysis, design and implementation. These four activities form should be applied in an iterative fashion, allowing for user feedback and requirements and system evolution.

Whitson [23] described a web development process (WebHelix) for the development of

web applications. This model consists of project management plan that creates a task list from a systems architecture diagram and uses chart to synchronize the team workload. The WebHelix methodology used a modified spiral approach to systems’ development. Some parts of the design process, like the business analysis and planning, are done once at the beginning of the process. Some parts of the process, like deployment and maintenance are done once at the end of the process. The major creation of the web application is done by using set of steps repeatedly, producing a set of more complete prototypes, with the final prototype being the completed web application. A WebHelix process consists of the business success evaluation, planning, analysis, design, coding and integration, testing, evaluation, deployment and training, maintenance and future updates.

Crane and Clyde [24] described a lightweight two-phase process that integrated

advantages from incremental development, throwaway prototyping and waterfall process models to address the challenges of development of web applications such as: frequent changes in requirements; time and cost constraints; and producing quality user interfaces within the

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restrictions of the web environment. Their process consists of cascading phases of interdependent waterfall models. Phase1 follows a modified incremental development model with an emphasis on rapid prototyping and involves the iteration of development activities (requirements definition, systems analysis, design, coding and testing). Phase1 helps the development team to understand the requirements and adapt to frequent changes. Whereas phase2 follows waterfall model with an emphasis on quality and consists of well-defined steps that correspond closely to development activities. Unlike phase1, progress is measured in terms of completion of development activities, instead of the completion of features. Phase2 builds on the knowledge gained from the phase1 and produces a product that has a better user interface, more extensible and maintainable.

Zhao and Chen [25] proposed a component-oriented model of web application in which

a web application is regarded as a collection of components. Each component have its own functionality and cooperating with others through certain interfaces. They aimed to establish a foundation for methodology to effective development and maintenance of web application that can benefit from the notion of component-oriented approach. Under this model a web application is consisted of client components and server components. All components expose their functionality through interfaces. The client component of a web application will carry out all the tasks at the client side including interacting with end users and any other related activities. The server component takes care of all the processing works to happen at the server side and they do not have user interfaces. This model designed to be used at the application definition phase only during the development process to capture the features of web applications. This model lacked systematic and engineering methodology that can cover the whole lifecycle of web applications.

Bochicchio and Paiano [26] discussed a design/prototyping environment and presented

the definition and features of JWeb (an environment to support design and prototyping of complex WWW sites). They discussed reasons of why an environment supporting design/prototyping is useful such as: support in the early stage; multi delivery; technological flexibility; design advanced options; and design incompleteness. The JWeb system is a design environment with fast prototyping capabilities based on the hypermedia design methodology (HDM) with the following features: it supports design of the hyper-base and access structures; it supports a clean separation between design in the large and design in the small; and it allows building an environment based on a relational DB to hold the multimedia contents. In many cases they used the prototype as initial version of the application to be worked on in

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order to build up the final version. Sometimes, the prototype could be used as an implementation platform. Finally, we can say that, they didn’t discuss design models.

Bochicchio and Fiore [27] described an environment (tool) named WARP (Web

Application Rapid Prototyping) for the analysis and the rapid prototyping of web applications. This environment offers a set of online software tools, which assist the designer and the user browsing of a web application in all its different aspects. The environment is based on models and techniques used in the hypermedia, information systems and software engineering fields, adapted and mixed. The WARP project proposed a methodology and a development environment for fast prototyping of web applications which support the development cycle from requirement analysis and design of the information and system features till the detailed definition of these schemas and the production of applications (coding, database creation, database filling and creation of interfaces). The process of developing a web application with WARP consists of many steps: collection of requirements; generation of the supporting database; management of the contents; and definition of presentation aspects. After the prototype has created, it must be evolved to create the final web application [27].

Griffiths, et. al. [28] proposed simple web method (SWM) for web engineering. They

had built and introduced the prototype WIPSE (Web Integrated Project Support Environment) called PAWS (Project Administration Web Site) that implements some of these whole life cycle activities and to support web engineering. They introduced the following stages and techniques in SWM: project planning; analysis (statement of purpose, audience definition, content analysis and modeling, constraint analysis, and marketing analysis and planning); design (structure/web architecture, page design, visual style, navigation, and metaphor definition); building (preparation, prepare content, build web site, test and evaluate and launch); and maintenance.

All of these above efforts offered facilities to speed up design and development of web applications. However, none of them provided an efficient support for the end-to-end process of generation and maintenance of whole web applications.

1.7.2 Literatures related to development methodologies of large web applications

A summary and analysis of literatures related to development process of large-scale web applications is given below:

Aoyama [29] proposed an agile software development process (ASP) in order to meet the

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the flexibility needed that respond to requirements changing. This ASP model consists of upper stream process which covers analysis to implementation phases and the lower stream process which covers the integration testing and system testing phases. The upper stream process consists of several concurrent software processes assigned across multiple teams at geographically distributed sites. When each team completed its upper stream process, it checks in the system to be integrated into a whole system through the lower stream process of integration testing and system testing.

McDonald and Welland [30] described the agile web engineering (AWE) process for the

development of web applications. They discussed and identified the interaction between business, domain, software and creative design within web projects in their AWE process to deliver solutions that satisfy users. They outlined the AWE process life cycle detailing each stage and how the stages should be used an iterative approach. They identified the various stakeholders that should be reflected within the AWE Process. They discussed how to apply AWE to the development of large web applications with one hundred developers by broken down the developers into smaller teams and each team views the deliverables of other teams through a set of interfaces, one team was responsible for user interface, one for database design, and one for testing system. Each team works on a different type of problem but it may be not systematic process because one team may be wait long time in order to operate on the delivery of previous team.

Ginige and Murugesan [31] proposed approach to developing large web systems that is

consists of methodologies that enable developers to successfully developing large web applications. They addressed that, there is a need for process to be used in building web systems that assists developers in managing the changing requirements, complexity of the development process, facilitates the communication among members involved in the development process, and supports the continuous evolution, maintenance and management of the content. Their model consists of context analysis, product model, process model, sub project planning, web site development (web site design and construction), web site maintenance, project management, documentation and quality control and assurance.

Next to the above research, Ginige [32] highlighted the need to have an appropriate process model when developing large and maintainable web applications. He suggested a process to get user feedback during requirements analysis phase. This process consisted of explicit steps to get feedback from the client at regular intervals. He integrated this process with the overall development model that was already suggested in the previous research.

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Finally, he suggested that, doing high-level analysis and planning when developing large web applications in order to meet customer requirements within an agreed time frame and budget.

Tai et. al. [33] described a model-driven approach to support the development of large

web applications. They focused on dividing the large development into a number of smaller tasks of different kinds that can be performed by multiple developers to manage the consistency among the sub tasks in an efficient manner. They presented the problems in web application’s development such as wide range of technologies involved and a lack of support for the division of work. They suggested that, when web applications grow in size, they are built using various kinds of technologies. They suggested as a one possible solution, the division of design and implementation work and to assign the divided work tasks to a number of developers. Theyillustrated the development style that categorizes the developer roles and listed the developer roles as screen designers, model maintainers, business logic programmers, server object programmers and application assemblers.

Maring [34] suggested four principles to improve the likelihood of success in applying

OO development methods in large organizations. The first principle: all control-flow or dynamic behavior should be encapsulated and represented as a design-time abstraction. Second: all business rules that are to change over an application’s life should be represented as a single-rules object that business managers can manage. Rule operators and values should be bound dynamically to behaviors and should not be hard-coded as part of the class behavior. Third: class attributes should be mapped to share persistent storage outside of class behaviors. Knowledge of persistence and schemas should not be hard-coded class behaviors. Fourth: class templates should be used to ensure consistency, completeness and testability. He suggested in this research the use of a reuse-centric development process rather than a coding-centric process.

He addressed that, the reuse goals should be accompanied by cultural change. Thus, the challenge of cultural change rests more with the management team than with the programmers. He addressed that, there should be a single OO Meta model object to deals with basic object properties, how objects communicate with other objects, and how dynamic behaviors are handled. Finally, he suggested managing class libraries by: minimize sub classing; clarify class abstractions; eliminate behavior overrides; and organize for reuse.

Ericsson [35] suggested dividing the large system (super system) into several separate

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system is implemented by a set of interconnected systems communicating with each other to fulfill the work of this super system. He introduced an architectural pattern for systems of interconnected systems. Each involved system is described by its own set of models, separate from other systems’ models. Each subordinate system is developed using RUP as a black box considering other systems with which it communicates as actors. This construct allows recursion within one model, and it considers each subsystem a system in its own right and the recursion is between all the artifacts sets of each of the systems. This technique suggested performing the requirements workflow, analysis and design for the subordinate system to understand the boundaries of the subordinate system and what its actors are. The drawback is that you risk more overhead, desynchronized schedules, and it is very hard to employ an iterative lifecycle to the super ordinate system in organizations.

1.8 The Literature Analysis (

Problems Obtained from Literature)

It becomes more critical to support the development of large web application when the web application is growing in size. This research focuses on problems and challenges that most or even all of the earlier researches and organizations did not take in their considerations when developing the large web applications. These problems are as follows:

1. Most of these earlier researches focused on parts of development process such as requirements, analysis, design or implementation and did not consider the overall development process of large web applications.

2. Most of earlier researches focused on developing a web application in general and did not consider the web application’s size if it is small, medium or large sized.

3. Most of earlier researches in the case of large web application did not consider the size of development team and how to manage this large number of developers.

4. Most or even all of the earlier researches did not give details about the requirements’ elicitation, analysis and management, stakeholders and stakeholders’ roles in the case of large web applications.

5. Most or even all of earlier researches talked about the large system as a whole and did not talk about how to simplify this large system and how to integrate, test, maintenance, and management of the overall large system.

6. Most of earlier researches did not talk about the management methodology to manage and coordinate the overall development process of large web applications.

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7. Most of earlier researches did not integrate the properties of agile methods such as customer communication and feedback, pair programming and requirements changing during development process with the steps of web development process model.

8. All of earlier researches lacked risk analysis and risks types during the development of large web applications.

1.9 The Research Methodology

Figure (1.2) shows the methodology of this research. The brief description points of the research methodology are as follows:

1. At the beginning of this research, we give a description of web engineering, web-based applications and development process of web applications.

2. Listing of the literature studies that defined the large web applications. Building a simple questionnaire (see Appendix A) according to the definitions of large software/projects mentioned in these literature studies. We distributed this questionnaire to many Jordanian enterprises which undertaken development of web applications.

3. The selection of only large Jordanian enterprises as our research population. The selection of large enterprises is done according to the analysis of first questionnaire’s results and also according to the interviews with managers working in these Jordanian enterprises that followed this questionnaire.

4. Listing of the previous literature studies related to development methodologies of web applications and highlighted their strengths and limitations. The literature studies included the methodologies that used different approaches of traditional software process models and the web engineering process models in developing web applications. There are few literature researches which undertaken developing of the large web applications.

5. Listing of current and previous literature related to traditional software methodologies (Waterfall, Spiral, Prototyping, et.), agile methodologies (XP, Scrum, et.), software process improvement models (CMM, CMMI, and ISO).

6. Do a survey in the selected large Jordanian enterprises: This survey is divided into two parts. The first part is a second deeper questionnaire (see Appendix B) and the second part is an interview followed this questionnaire. The contents of this questionnaire are determined according to questions reported in the Software Best Practice Questionnaire (SBPQ) which was attached with the report [36]. The units of analysis for this survey are large-scale Jordanian enterprises which undertaken the development of large web applications.

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7. The importance of this second questionnaire is to obtain: developers’ characteristics; the practices used for web engineering; software development methodologies used; and the symptoms that faced these large enterprises. We will adopt the using of the SPSS statistical analysis tool in order to analyze the results of the second questionnaire.

8. Proposing a web engineering process model to support the suitable development of large web applications within the time, budget and effort and overcome as possible as the problems of web development in literature researches and in large enterprises. The proposing of this web engineering model is very important to meet the web engineering challenges and problems. At the end of this research we will answer the four questions listed earlier in point 3 in research objectives.

9. Analyzing the compatibility of this proposed model with the SPI CMMI key process areas and goals to determine the position of this model among CMMI levels.

10. Comparing the proposed model with many other traditional, agile and web engineering

process models according to their compatibilities with SPI CMMI KPA’s and goals.

11. Evaluating the proposed model by the aiding of professional developers and managers currently working in different large Jordanian enterprises which undertaken large web development. This evaluation will depend on the CMMI KPA’s and goals to determine which CMMI level can be reached when adopting this proposed model by any large web development enterprise.

1.10 Outlines of the Thesis

This thesis is divided into seven chapters: Chapter One will include the description of web application, web engineering, development process of web applications and large web applications. Chapter1 will address the importance of this research, problems in developing large web applications and research objectives. Chapter1 will include also the literature review, literatures related to development methodologies of web applications, literatures related to development methodologies of large web applications and analysis of these literatures. Finally, chapter1 will present the research methodology.

We will give in Chapter Two details about software types, web applications, differences between web-based applications and traditional software, and challenges of web applications development. Chapter2 will include a description of software development process, the perceived problems in software development, the basics of good software development, ad-hoc development, the importance of software process in large organizations, and many well known traditional software process models. Chapter2 will include also a description of agile

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process methodologies, extreme programming, introducing agile methodologies in large organizations, the differences between agile and traditional methodologies, and how to mix agile methods with traditional methods. Finally, we will give in chapter2 details about the development process of web applications, the factors responsible for the failure of web applications, steps for successful development of web applications, requirements engineering, modeling, design models, cost estimation, stakeholders, project planning, management, tools, testing and the documentation of web applications.

Chapter 1

Description of web engineering, web-based applications, and development process of web applications

In Chapter Three, we will give a description of SPI, CMM, CMMI, CMMI levels and its KPA’s, organizations with CMM experience and ISO concepts. Chapter3 will include also the importance of SPI, CMMI for large enterprises, lack of researches about SPI for large

Listing the literature studies that defined large web applications

Build Questionnaire1 and distribute it on web development Jordanian enterprises

Selection of only the large-scale Jordanian enterprises

Listing the literature researches related to development methodologies of web applications

Literature analysis and obtain literature problems

Listing of literature related to traditional software methodologies

Listing of literature related to agile methodologies

Listing of literature related to software process improvement models (CMM, CMMI, and ISO), and software quality assurance (SQA)

Questionnaire2 on large Jordanian enterprises which undertaken web development

Obtain problems and challenges of these selected large enterprises SPSS statistical analysis tool

Proposing a web engineering process model

Model Evaluation according to CMMI key process areas and goals

Chapter 1 Chapter 1 Chapter 4 Chapter 1 Chapter 4 Chapter 2 Chapter 4 Chapter 2 Chapter 4 Chapter 3 Chapter 4 Chapter 5 Chapter6

Model comparisons with other traditional, agile, and web engineering process models Chapter6

A Proposed Hybrid Web Engineering Process Model for Large-Scale Web-Based Applications Development in Large Web Development Enterprises