1. Requirements Analysis 21. 1 Moving to Design - 2005b521.ppt © Copyright De Montfort University 2000 All Rights Reserved INFO2005 Requirements Analysis Moving to Design Department of Information Systems

2. Requirements Analysis 21. 2 Moving to Design - 2005b521.ppt © Copyright De Montfort University 2000 All Rights Reserved Learning Objectives v Examine the issues that have to be addressed during design v Distinguish between System and Object Design v Consider the impact of implementation technology v UP, Design and Implementation

3. Requirements Analysis 21. 3 Moving to Design - 2005b521.ppt © Copyright De Montfort University 2000 All Rights Reserved Analysis vs Design  Why separate analysis and design  Project Management,  Staff Skills and Experience,  Client Decisions  Choice of Development Environment.

4. Requirements Analysis 21. 4 Moving to Design - 2005b521.ppt © Copyright De Montfort University 2000 All Rights Reserved What makes a good analysis v To provide a sound foundation for design, analysis should meet the following four criteria:

5. Requirements Analysis 21. 5 Moving to Design - 2005b521.ppt © Copyright De Montfort University 2000 All Rights Reserved What makes a good design

6. Requirements Analysis 21. 6 Moving to Design - 2005b521.ppt © Copyright De Montfort University 2000 All Rights Reserved What makes a good design

7. Requirements Analysis 21. 7 Moving to Design - 2005b521.ppt © Copyright De Montfort University 2000 All Rights Reserved Measurable Objectives v Information systems are built to satisfy an organisational need such as v Measurable objectives might include v However not all objectives are quantifiable

8. Requirements Analysis 21. 8 Moving to Design - 2005b521.ppt © Copyright De Montfort University 2000 All Rights Reserved Logical vs Physical Design v One way of separating design by splitting it into –Logical design –Physical design

9. Requirements Analysis 21. 9 Moving to Design - 2005b521.ppt © Copyright De Montfort University 2000 All Rights Reserved Logical vs Physical Design v Physical design is affected by

10. Requirements Analysis 21. 10 Moving to Design - 2005b521.ppt © Copyright De Montfort University 2000 All Rights Reserved Logical vs Physical Design v Logical design is concerned –how objects interact determining

11. Requirements Analysis 21. 11 Moving to Design - 2005b521.ppt © Copyright De Montfort University 2000 All Rights Reserved Logical vs Physical Design v One logical design leads to various physical designs (and implementations). v Distinction made much less these days v System architecture enables different styles of implementation

12. Requirements Analysis 21. 12 Moving to Design - 2005b521.ppt © Copyright De Montfort University 2000 All Rights Reserved System and Object Design v System Design is concerned with v Object Design is

13. Requirements Analysis 21. 13 Moving to Design - 2005b521.ppt © Copyright De Montfort University 2000 All Rights Reserved System Design v Sub-systems and major components are identified. v Any inherent concurrency is identified. v Sub-systems are allocated to processors.

14. Requirements Analysis 21. 14 Moving to Design - 2005b521.ppt © Copyright De Montfort University 2000 All Rights Reserved System Design v A data management strategy is selected. v A strategy and standards for human- computer interaction are chosen. v Code development standards are specified.

15. Requirements Analysis 21. 15 Moving to Design - 2005b521.ppt © Copyright De Montfort University 2000 All Rights Reserved System Design v The control aspects of the application are planned. v Test plans are produced. v Priorities are set for design trade-offs. v Implementation requirements are identified (for example, data conversion). v Architectural patterns may be used.

16. Requirements Analysis 21. 16 Moving to Design - 2005b521.ppt © Copyright De Montfort University 2000 All Rights Reserved System Design A typical software architecture Bennett, McRobb, Farmer, 1999

17. Requirements Analysis 21. 17 Moving to Design - 2005b521.ppt © Copyright De Montfort University 2000 All Rights Reserved UML packages representing layers in the three-tier architecture Bennett, McRobb, Farmer, 1999

18. Requirements Analysis 21. 18 Moving to Design - 2005b521.ppt © Copyright De Montfort University 2000 All Rights Reserved Detailed or Object Design v This involves making decisions regarding

19. Requirements Analysis 21. 19 Moving to Design - 2005b521.ppt © Copyright De Montfort University 2000 All Rights Reserved Object Design Bennett,McRobb,Farmer, 1999

20. Requirements Analysis 21. 20 Moving to Design - 2005b521.ppt © Copyright De Montfort University 2000 All Rights Reserved RUP Phases v Inception –business case –plan v Elaboration –use cases –baseline architecture v Construction –product is built v Transition –beta release/testing/training Rational Unified Process

21. Requirements Analysis 21. 21 Moving to Design - 2005b521.ppt © Copyright De Montfort University 2000 All Rights Reserved The Rational Unified Process Rational Unified Process

22. Requirements Analysis 21. 22 Moving to Design - 2005b521.ppt © Copyright De Montfort University 2000 All Rights Reserved The Analysis & Design Workflow Rational Unified Process 2000

23. Requirements Analysis 21. 23 Moving to Design - 2005b521.ppt © Copyright De Montfort University 2000 All Rights Reserved Design Activities v Centred around the software architecture v Production of the Design Model

24. Requirements Analysis 21. 24 Moving to Design - 2005b521.ppt © Copyright De Montfort University 2000 All Rights Reserved Implementation & UP v 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. Requirements Analysis 21. 25 Moving to Design - 2005b521.ppt © Copyright De Montfort University 2000 All Rights Reserved Summary v Examine the issues that have to be addressed during design v Distinguish between System and Object Design v Consider the impact of implementation technology v UP, Design and Implementation

26. Requirements Analysis 21. 26 Moving to Design - 2005b521.ppt © Copyright De Montfort University 2000 All Rights Reserved References v Bennett, S. et. al. “Object-Oriented Systems Analysis & Design using UML” McGraw-Hill 2002 v Jacobson, I., Booch, G. & Rumbaugh, J. (1999) “The Unified Software Development Process” Addison- Wesley v Rational Unified Process Best Practices for Software Development Teams White Paper, 1998 www.rational.com v Rational Unified Process 2000