INFO2005 Requirements Analysis Moving to Design

1. INFO2005Requirements AnalysisMoving to Design Department of Information Systems

2. Learning Objectives • Examine the issues that have to be addressed during design • Distinguish between System and Object Design • Consider the impact of implementation technology • UP, Design and Implementation

3. Analysis vs Design • Why separate analysis and design • Project Management, • Staff Skills and Experience, • Client Decisions • Choice of Development Environment.

4. What makes a good analysis • To provide a sound foundation for design, analysis should meet the following four criteria:

5. What makes a good design

6. What makes a good design

7. Measurable Objectives • Information systems are built to satisfy an organisational need such as • Measurable objectives might include • However not all objectives are quantifiable

8. Logical vs Physical Design • One way of separating design by splitting it into • Logical design • Physical design

9. Logical vs Physical Design • Physical design is affected by

10. Logical vs Physical Design • Logical design is concerned • how objects interact determining

11. Logical vs Physical Design • One logical design leads to various physical designs (and implementations). • Distinction made much less these days • System architecture enables different styles of implementation

12. System and Object Design • System Design is concerned with • Object Design is

13. System Design • Sub-systems and major components are identified. • Any inherent concurrency is identified. • Sub-systems are allocated to processors.

14. System Design • A data management strategy is selected. • A strategy and standards for human-computer interaction are chosen. • Code development standards are specified.

15. System Design • The control aspects of the application are planned. • Test plans are produced. • Priorities are set for design trade-offs. • Implementation requirements are identified (for example, data conversion). • Architectural patterns may be used.

16. System Design A typical software architecture Bennett, McRobb, Farmer, 1999

17. UML packages representing layers in the three-tier architecture Bennett, McRobb, Farmer, 1999

18. Detailed or Object Design • This involves making decisions regarding

19. Object Design Bennett,McRobb,Farmer, 1999

20. RUP Phases • Inception • business case • plan • Elaboration • use cases • baseline architecture • Construction • product is built • Transition • beta release/testing/training Rational Unified Process

21. The Rational Unified Process Rational Unified Process

22. The Analysis & Design Workflow Rational Unified Process 2000

23. Design Activities • Centred around the software architecture • Production of the Design Model

24. Implementation & UP • The purpose of implementation is: • to define the organization of the code, in terms of implementation subsystems organized in layers, • to implement classes and objects in terms of components (source files, binaries, executables, and others), • to test the developed components as units, and • to integrate the results produced by individual implementers (or teams), into an executable system.

25. Summary • Examine the issues that have to be addressed during design • Distinguish between System and Object Design • Consider the impact of implementation technology • UP, Design and Implementation

26. References • Bennett, S. et. al. “Object-Oriented Systems Analysis & Design using UML” McGraw-Hill 2002 • Jacobson, I., Booch, G. & Rumbaugh, J. (1999) “The Unified Software Development Process” Addison-Wesley • Rational Unified Process Best Practices for Software Development Teams White Paper, 1998 www.rational.com • Rational Unified Process 2000