1. Web-Based Systems: Initial Questions
 What is a Web-Based System?
 How is it build?
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2. What Is a Web-Based System?
 “A software system based on technologies and standards of
the World Wide Web Consortium (W3C) that provides Web
specific resources such as content and services through a user
interface, the Web browser” (Kappel et al.)
 Therefore, this definition excludes:
 Web sites without software components (e.g. static HTML
pages)‫‏‬
 Web services
 Web-Based System = Web Application
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3. Categories of Web-Based Systems
Ubiquitous
Semantic-Web
COMPLEXITY
Social-Web
Collaborative
Workflow-
Based
Portal-
Transactional Oriented
Interactive
Document-
Centric
DEVELOPMENT HISTORY
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4. Characteristics of Web-Based Systems
 Network intensiveness
 Internet
 Intranet
 Global reach and Unpredictability
 Who are the users?
 Usage patterns
 Backgrounds: language, culture, age, education, ...
 How many users?
 Potential / Occasional / Frequent users
 Concurrency: average, peaks
 Competition and Differentiation
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5. Characteristics of Web-Based Systems
 Space / Time
 Internationalization
 Location-aware services
 Availability
 Hypertext
 No-linearity
 Navigation
 Content-driven
 Document-centric
 Multimedia
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6. Characteristics of Web-Based Systems
 Look and feel
 Usability
 Accessibility
 Aesthetics
 Continuous Evolution
 Security
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7. Technologies for Web-Based Systems
 Web Standards
 HTTP, HTML, XML, CSS, etc
 Programming Languages:
 PHP, Javascript, Perl, Java, C#, etc
 Component Frameworks:
 J2EE: Servlets, JSP, EJB
 .NET: ASP.NET
 Web Frameworks:
 PHP: Symfony, Mojavi, CakePHP, Prado, etc
 Java: Struts, Spring, Tapestry, Turbine, Webworks, etc
 Security:
 Firewalls, Cryptography, Authentication
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8. Web Engineering
 “Web Engineering is the application of systematic and
quantifiable approaches (concepts, methods, techniques,
tools) to cost-effective requirements analysis, design,
implementation, testing, operation, and maintenance of high-
quality Web applications”. (Kappel et al.)
 A Web Engineering Process must accommodate
 Incremental delivery
 Frequent changes
 Short timeline
 Therefore,
 An incremental process model should be used in virtually all
situations (e.g. RUP)‫‏‬
 An agile process model is appropriate in many situations
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9. The Web Engineering Process
Acceptance test Coding
Customer’s‫‏‬feedback Component testing
Release
Design models
Analysis models
Umbrella activites
Business analysis
Vision document Change management
Iteration plan Quality assurance
Risk management
Project management
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10. Web Engineering: Techniques and Tools
 Communication among participants
 Formal/informal meetings, documentation, e-mail, demos,
project management tools, etc.
 Requirements elicitation
 Communication with stakeholders, vision documents, use
cases, CASE tools, etc.
 Modeling
 UML artifacts, design patterns, CASE tools, etc.
 Construction
 Programming techniques, code editors, compilers, version
management, installers, IDE, open source code, etc.
 Testing
 Strategies, tools, etc.
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11. Web Engineering: The People
 Domain experts
 Content developers/providers
 Web editors
 Web engineers: We!
 Support team
 System evolution: patches, adaptations, improvements
 Administrator (webmaster)‫‏‬
 Statistics, tuning, security, etc
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12. References
 R. G. Pressman, D. Lowe: Web Engineering. A Practitioner’s
Approach. McGraw Hill, 2008. Chapters 1-2.
 KAPPEL, Gerti et al: Web Engineering. Wiley, 2006. Chapter 1.
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