1dsbw 2011/2012 q1

What is a Web-Based System?

How is it build?

Web-Based Systems: Initial Questions

2dsbw 2011/2012 q1

“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

What Is a Web-Based System?

3dsbw 2011/2012 q1

Categories of Web-Based Systems

DEVELOPMENT HISTORY

CO

MP

LE

XIT

Y

Document-Centric

Interactive

Transactional

Workflow-Based

Collaborative

Social-Web

Portal-Oriented

UbiquitousSemantic-Web

4dsbw 2011/2012 q1

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

Characteristics of Web-Based Systems

5dsbw 2011/2012 q1

Space / Time

Internationalization

Location-aware services

Availability

Hypertext

No-linearity

Navigation

Content-driven

Document-centric

Multimedia

Characteristics of Web-Based Systems

6dsbw 2011/2012 q1

Look and feel

Usability

Accessibility

Aesthetics

Continuous Evolution

Security

Characteristics of Web-Based Systems

7dsbw 2011/2012 q1

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

Technologies for Web-Based Systems

8dsbw 2011/2012 q1

“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

Web Engineering

9dsbw 2011/2012 q1

The Web Engineering Process

Release

Iteration plan

Design models

Analysis models

Business analysis

Vision document

Acceptance test

Customer’s‏feedback

Coding

Component testing

Change management

Quality assurance

Risk management

Project management

Umbrella activites

10dsbw 2011/2012 q1

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.

Web Engineering: Techniques and Tools

11dsbw 2011/2012 q1

Domain experts

Content developers/providers

Web editors

Web engineers: We!

Support team

System evolution: patches, adaptations, improvements

Administrator (webmaster)‏

Statistics, tuning, security, etc

Web Engineering: The People

12dsbw 2011/2012 q1

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.

References