CSC340: Tutorial 3 Software Lifecycles and Prototyping

1. CSC340: Tutorial 3Software Lifecycles and Prototyping TA: Y. An Date: 9:00-10:00am, Fri. Oct. 17, 2003 Location: BA1130 CSC340

2. In This Tutorial: • Managing Information Systems Development. • User Involvement. • CASE tools. CSC340

3. Managing IS Development • An information system development project has many attendant risks: • Late delivery may result in: • Lost income; • Punitive legal action. • The continuing ability of competing effectively may be dependent upon a new IS. • Failure to deliver a new system may even cause a company to fail. CSC340

4. Managing Risks at Each Stage • It is important at each stage to identify risks to the organization and determine their significance so that judgements can be made on the continuing viability of the project. • In spiral life cycle, each iteration includes a risk assessment. CSC340

5. User Involvement • Users can be involved in various ways • As part of the development team (DSDM) • Via a consultative approach • In fact gathering CSC340

6. As Part of the Development Team • Having a significant opportunity to influence the way the project proceeds – by identifying difficulties and suggesting more acceptable alternatives. • Users may cease over time to represent the user perspective effectively, as viewing themselves as team members. • Rotating membership of the development team among a group of users. CSC340

7. Via a Consultative Approach • Users are able to review certain aspects of the systems development, provide feedback, give their views of the system, and be able to see developers’ response. • Not enough training is given. Terminology and models used by developers may not be understood by users. Not enough and designated time is given to users for reviewing. CSC340

8. Fact Gathering • Users provide information about current working practice but they have little or no influence on the design of the new system. • They may be less co-operative and will be less willing to take ownership of the new system when it is installed. CSC340

9. User Involvement (con’t) • The traditional waterfall life cycle is less amenable to user involvement throughout the whole project and is less likely to amenable with the changes of user requirements. • The prototyping approach is normally dependent upon continuing user involvement and encourages user involvement. • However, the evaluation of prototype requires significant time from the users. CSC340

10. User Involvement (con’t) • It is important that user’s role is carefully explained and that training is given as required. • User can be designated by management as being the most appropriate representative. • Or, user can be selected by their peers. CSC340

11. Computer Aided Software Engineering • CASE tools typically provide a range of features including • checks for syntactic correctness • repository support • checks for consistency and completeness • navigation to linked diagrams • layering • requirements tracing • report generation • system simulation • performance analysis • code generation CSC340

12. The Waterfall Life Cycle Model CSC340

13. The Waterfall Life Cycle with Iteration Iteration added to solve some of the problems CSC340

14. Prototyping CSC340

15. Spiral Life Cycle Model CSC340

16. The Spiral Life Cycle Model CSC340

17. Unified Software Development Process • Captures many elements of best practice • Main phases • Inception is concerned with determining the scope and purpose of the project • Elaboration focuses requirements capture and determining the structure of the system • Construction's main aim is to build the software system • Transition deals with product installation and rollout CSC340

18. Project Phases Workflows Requirements Analysis Design Implementation Test Inception 1 2 3 Size of square relative to time spent on workflow Elaboration 4 5 Construction 6 7 8 Transition 9 10 Iterations within each phase CSC340