1. Web-Based Systems: Initial Questions
What is a Web-Based System?
How is it build?
dsbw 2008/2009 2q 1

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”
 Therefore, this definition excludes:
Web sites without software components (e.g. static HTML

pages)
 Web services
 Web-Based System = Web Application
dsbw 2008/2009 2q 2

3. Categories of Web-Based Systems
Ubiquitous
Semantic-Web
COMPLEXITY
Social-Web
Collaborative
Workflow-
Based
Portal-
Oriented
Transactional
Interactive
Document-
Centric
DEVELOPMENT HISTORY
dsbw 2008/2009 2q 3

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
dsbw 2008/2009 2q 4

5. Characteristics of Web-Based Systems
 Space / Time
 Internationalization
 Location-aware services
 Availability
 Hypertext
 No-linearity
 Navigation
 Content-driven
 Document-centric
 Multimedia
dsbw 2008/2009 2q 5

6. Characteristics of Web-Based Systems
 Look and feel
 Usability
 Accessibility
 Aesthetics
 Continuous Evolution
 Security
dsbw 2008/2009 2q 6

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
dsbw 2008/2009 2q 7

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”.
 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
dsbw 2008/2009 2q 8

9. The Web Engineering Process
Coding
Acceptance test
Component testing
Customer’s feedback
Release
Design models
Analysis models
Umbrella activites
Business analysis
Vision document
Change management
Quality assurance
Iteration plan
Risk management
Project management
dsbw 2008/2009 2q 9

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.
dsbw 2008/2009 2q 10

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
dsbw 2008/2009 2q 11

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.
dsbw 2008/2009 2q 12