Web Engineering Introduction and Perspective

1. Web EngineeringIntroduction and Perspective Bibhudatta Sahoo Department of CSE NIT Rourkela

2. Web engineering • Web engineering is way of developing and organizing knowledge about Web application development and applying that knowledge to develop Web applications, or to address new requirements or challenges. It is also a way of managing the complexity and diversity of Web applications. • Web engineering is application of scientific, engineering, and management principles and disciplined and systematic approaches to the successful development, deployment and maintenance of high quality Web-based systems and applications (Murugesan et al., 1999).

3. Motivation • The World Wide Web has become ubiquitous, and it continues to grow unabated at exponential rate • Increase in depend on Web-based systems and applications, • Demands for Web applications have increased significantly over the years.

4. Motivation • Short development life-cycle times. According to our results, the average development life-cycle time • is less than three months. This figure is dramatically lower than that of traditional software development. • If a Web engineering process is going to be successful, then it has to cope with exceptional time pressures.

5. Evolution and growth of the Web The evolution of the Web has brought together some disparate disciplines such as media, information science, and information and communication technology, facilitating easy creation, maintenance, sharing, and use of different types of information from anywhere, any time, and using a variety of devices such as desktop and notebook computers, pocket PCs, personal digital assistants (PDAs), and mobile phones.

6. Evolution and growth of the Web • Media:integration of different types of media such as data, text, graphics, images, audio and video, and their presentation ; different types of interaction and channels of communications. • Information science: information organization, presentation, indexing, retrieval, aggregation, and management; and collaborative and distributed content creation. • Information and communication technology and networking: efficient and cost effective storage, retrieval, processing, and presentation of information; infrastructures that facilitate transfer and sharing of data and information; wired and wireless Internet communication; and personalized and context-aware Web applications

7. Journey of Web Engineering 1990-1995 • World Wide Web originates- 1990 • Hypertext Markup Language written- 1991 • Text-based browser opens WWW for use- 1992 • New Web terms: HTTP and URL-1992 • Graphical user interface, Mosaic, developed- 1993 • HTML introduced as code for web design- 1993 • World Wide Web Consortium,W3C founded- 1994 1996-2001 • First Paper about Web Engineering related problems appear at the 5th WWW Conference in France-1996 • Microsoft releases Explorer 3.0 Web browse- 1996 • Web Engineering Homepage published WebEngineering.org -1997 • First workshop on Web Engineering organized at the 7th WWW Conference in Australia- 1998 • First International Conference on Web Engineering (ICWE)-2001

8. Journey of Web Engineering 2002-2005 • For the first time Web Engineering became part of the main program-2002 • First international Journal on Web Engineering published by Rinton Press, USA-2002 • Web Engineering became an area of the refereed paper track at the WWW conference, demonstrating • the emerging need for a discipline on development, operation, and evolution of Web applications-2003 • W3C describes principles of Web architecture-2004 W3C actively busy in standardizing protocols and • web technologies-2005

9. Anytime-Anywhere-Any media paradigm We are facing a new generation of web applications being characterized by the anytime/anywhere/anymedia paradigm, thus providing ubiquitous access to services, turning e-commerce into m-commerce.

10. Web based application WBAWeb-based Information Systems (WIS) • Web based application(WBA) defined as "any software application that depends on the Web for its correct execution" • The application of systematic, disciplined and quantifiable approaches to development, operation, and maintenance of Web-based Information Systems (WIS)

11. A well engineered Web system is: 1/2 • Functionally complete and correct • Usable • Robust and reliable • Maintainable • Secure • Perform satisfactorily even under flash and peak loads • Scalable • Portable, where required perform across different common platforms; compatible with multiple browsers

12. A well engineered Web system is: 2/2 • Reusable • Interoperable with other Web and information systems • Universal accessibility (access by people with different kinds disabilities) • Well-documented

13. Difference [Web, Software] Engineering • WBA have increased emphasis on user interface • Open modularized architectures • Link between business model and architecture • Rapidly changing technologies • More content-driven than software engineering. • Increased importance of quality attributes • Client uncertainty • Changing business requirements • Short time frames for initial delivery • Fine-grained evolution and maintenance • Highly competitive

14. Categories of Web Applications Based on functionality

15. Categories of Web applications based on functionality

16. Web Development Practices A Web development process outlines the various steps and activities of Web-based systems development. It should clearly define a set of steps that developers can follow and must be measurable and trackable. Characteristics of Web applications that make their development difficult — and uniquely challenging: • For real-time interaction, • complexity, • changeability, • the desire to provide personalized information

17. Characteristics of Web applications: • Web applications constantly evolve. • Web applications are inherently different from software. • Web applications are meant to be used by a vast, variable user community ( a large number of anonymous users)

18. Web application development process

19. The objectives of context analysis • Identify the stakeholders and their broader requirements and experiences. • Identify the functions the Web site needs to provide (immediately, and in the short, medium, and long term). • Establish what information needs to be on the Web site, how to get this information, and how often this information may change. • Identify the corporate requirements in relation to look and feel, performance, security, and governance. • Get a feel of the number of users (typical and peak) and anticipated demands on the system. • Study similar (competitive) Web sites to gain an understanding of their functionalities, strengths, and limitations.

20. Means of fulfilling the requirements of Web application

21. Means of fulfilling the requirements of Web application

22. Web page design

23. Attributes of quality Web-based systems • usability, • navigation, • accessibility, • scalability, • maintainability, • compatibility and interoperability • security and reliability

24. Web System Design: Challenges A flexible architecture that, facilitates greater reusability and quicker deployment. • Usability — interface design, navigation Comprehension, • Performance — responsiveness, • Security and integrity, • Evolution, growth, and maintainability, and • Testability.

25. A well engineered web system • Functionally complete and correct • Usable • Robust and reliable • Maintainable • Secure • Perform satisfactorily even under flash and peak loads • Scalable • Portable, where required perform across different common platforms; compatible • with multiple browsers • Reusable • Interoperable with other Web and information systems • Universal accessibility (access by people with different kinds disabilities) • Well-documented

26. How to test Web systems

27. Knowledge and Skills for Web Development • Technologies supporting and facilitating Web applications • Design methods • System architecture • Web development methods and processes • Web project management • Development tools • Content management • Web standards and regulatory requirements

28. Knowledge and Skills for Web Development [Design methods] • Design for usability — interface design, navigation • Design for comprehension • Design for performance — responsiveness • Design for security and integrity • Design for evolution, growth and maintainability • Design for testability • Graphics and multimedia design • Web page development

29. Web Page Design

30. Web engineering is specifically targeted toward the successful development, deployment and maintenance of large, complex Web-based systems.

31. Problems in large Web-basedprojects • Delivered systems didn't meet business needs 84 percent of the time. • Schedule delays plagued the projects 79 percent of the time. • Projects exceeded the budget 63 percent of the time. • Delivered systems didn't have the required functionality 53 percent of the time. • Deliverables were of poor quality 52 percent of time.

32. Areas that need further study • Web application delivery on multiple devices Context-aware Web applications and context-sensitive responses • Device-independent Web access and content presentation • Modelling and simulation of Web applications and systems • Performance evolution and enhancement • Testing and validation of systems • Effort and cost estimation • Web personalization • Quality control and assurance

33. Conclusion The essence of Web engineering is to successfully manage the diversity and complexity of Web application development, and hence, avoid potential failures that could have serious implications.

34. Conclusion Web Engineering is in its infancy but growing very fast. As participants in WBA development, we need to take our bearings fairly frequently and identify issues and problems, both philosophical and practical.

35. Reference [1] Yogesh Deshpande, Martin Gaedke "Web Engineering:Developing Successful Web Applications In ASystematic Way" 14th Intermational World Wide Web Conference, 10-14 May, 2005, Chiba, Japan. [2] R Ahmad, Z Li, F Azam "Web OPEN Integrated:Proposed Framework for Web Development",ISSN: 0302-9743, pp 533- 538, volume 3579 of Lecture Notes in Computer Science, Springer-Verlag, July 2005. [3] Gellersen, H.-W. and M. Gaedke. "Object-Oriented Web Application Development", IEEE Internet Computing 3 (1), 1999, pp. 60-68 [4] Deshpande Y, Murugesan S, Ginige A, Hansen S,Schwbe D, Gaedke M & White B "Web Engineering" Journal of Web Engineering, 1(1), 3-17, 2002 [5] Pressman, R S 'Sofiware Engineering: a Practitioner's Approach (4th ed.)',McGraw-Hill Publishing Company . [6] S. Overmyer, "What's different about requirements engineering for web sites?," Requirements Engineering Journal, vol. 5. no. 1, pp. 62-65. 2000. [7] Lowe, D., & Henderson-Sellers. B. "'Impacts on the development process of differences between web systems and conventional software systems",International Con/erence on Advances in Infrastructure for Electronic Business, Science, and Education on the Internet, L'Aquila, Italy, 2001 [8] T. Powell, D. Jones and D. Cutts: Web Site Engineering: Beyond Web Page Design. Prentice Hall,1998

36. Reference [10] Pressman, R S 'Can Internet-Based Applications Be Engineered?, IEEE Software, 15(5), 104-110, 1998 [11] "CERT/CC Overview" (D 1998-2003 by Camegie Mellon University [12] A.Ginige & S.Murugesan, "Web Engineering: An Introduction," IEEE MultiMedia, vol. 8, no. 1, Jan.- Mar. 2001, pp 14-18

37. Thank you ?

38. Thank you

39. Reference: Emilia Mendes Associate Professor Computer Science Department The University of Auckland Private Bag 92019 Auckland, New Zealand