Chapter 29 Web Engineering

Web Engineering is used to create high-quality Web-based systems and applications (WebApps). Web Engineering emphasizes the same philosophy of taking a disciplined approach to the technical and managerial activities of traditional software engineering.

Some of the differences are that many types of people are involved in creating WebApps, such as non-technical content developers and a wide range of end-users, and a variety of new tools are available. Web Engineering is not yet widely practiced, yet should be, considering the widespread use, and increasing complexity and sophistication, of WebApps.

Web-based Applications (WebApps) are:

• Network Intensive
• Content-driven - often multi-media
• Continuously evolving
• Immediately available
• Difficult to secure
• Aesthetically as well as technically designed

Web engineers should be concerned more with designing a robust, reliable, and maintainable infrastructure, than with the content, which is likely to change frequently and indefinitely.

Web Application Quality (like other software systems):

• Usability (interface, feedback)
• Functionality (search/retrieve, navigation)
• Reliability (error recovery, input validation)
• Efficiency (response time, page speed)
• Maintainability (ease of update, adaptability)

Web Development Technologies

• Component-based infrastructure development
  • e.g., CORBA, COM/DCOM, JavaBeans standards
• Security
• Internet standards: HTML, XML

Iterative Process Model for Web Development

• Formulation/Planning/Analysis/Engineering/Testing/Evaluation
• Design: Architecture, Navigation, Interface, Content, Production
• Goals, objectives, scope, cost, risk, schedule: all still apply

Formulation

• Customer and developer establish common goals
  • Why needed, who will use, what information, what tasks
  • User profile
• Scope
• Data, functional, behavioral requirements

Analysis

• content, interaction, functionality, configuration
• documented to pass to Web designer(s)

Design

• Hypermedia rules and methods, patterns, templates
• Structures: linear, grid, hierarchical, networked
• User roles = levels of access
• Interface: reliability, consistency, simplicity, clarity

Testing

• Content errors, navigation errors
• Unit testing, integration testing
• Controlled and monitored set of end-users

Web Project Management

• Multidisciplinary Project Team:
  • content provider, publisher, engineer, support, administrator
• Web projects often outsourced
• Initiation:
  • goals, audience(s), deliverables, measures of success
• Rough design: scope, expect incremental changes
• Schedule: relatively short, frequent milestones
• Contractor oversight and interaction plan
• Request for quote
• Vendor selection (interviews, samples, experience, fit)
• Cost/benefit analysis
• Change/configuration management
  • content, people, scalability, politics
  • SCM process: flexible, easy to understand
  • control over many distributed objects

Study Guide:

Key words:

Be able to :

• Compare traditional software engineering with Web engineering (similarities and differences)
• List attributes of WebApp quality
• Describe the iterative process model for Web development
• List and compare WebApp architectures (linear, grid, hierarchical, networked)
• List guidelines for WebApp user interface design
• Describe the array of skills required on a WebE team
• Explain the steps needed to effectively outsource a WebApp project

Suggested Exercises:

4, 5, 9, 11, 17, 18