1. Web Engineering Introduction 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
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
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
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 WBA Web-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
Category
Example
Informational
Online newspapers, product catalogues, newsletters, manuals, reports, online classifieds, online books
Interactive
Registration forms, customized information
presentation, online games
Transactional
Online shopping (ordering goods and services), online banking, online airline reservation, online payment of Bills

15. Categories of Web applications based on functionality
Category
Example
Workflow oriented
Online planning and scheduling, inventory
management, status monitoring, supply chain
Management
Collaborative work
environments
Distributed authoring systems, collaborative design tools
Online communities,
marketplaces
Discussion groups, recommender systems, online marketplaces, e-malls (electronic shopping malls), online auctions, intermediaries

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
Means of Fulfillment
Uniform look and feel across all Web pages that can easily be modified
Creation of Web pages using templates and style sheets
Consistency of information that may appear in different places or pages
Storing information in a single place (such as in a database or as an XML file), without duplication of information in different places or databases, and retrieving the required information for presentation where and when needed
Ease of information update and maintenance
Provision of a back-end system to edit information in a data repository; could have Web interface for easy access from anywhere
Ability to add new Web pages easily
Dynamic generation of navigational links, rather than predetermined static navigational links

21. Means of fulfilling the requirements of Web application
Means of Fulfillment
Decentralized system administration
Provision of a multi-user login system to access back-end systems and inclusion of a “user administration system” that can assign specific functions and data sets to content managers and other developers/administrators
Mechanisms for quality control and assessing the relevance of information
Inclusion of metadata for Web pages; use of a Web robot for gathering salient information, processing the information gathered and taking appropriate action(s) for ensuring quality or relevance of information presented.
Increased probability of being found through search engines
Using meta tags and registering with search Engines

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 Browser compatibility Page display
Session management
Usability
Content analysis
Availability
Backup and recovery
Transactions
Shopping, order processing
Internalization
Operational business procedures
System integration
Performance
Login and security

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-based projects
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, May, 2005, Chiba, Japan.
[2] R Ahmad, Z Li, F Azam "Web OPEN Integrated:Proposed Framework for Web Development",ISSN: , pp , 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
[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
[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), , 1998
[11] "CERT/CC Overview" (D 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