1. 1 9 Moving to Design Lecture 4

2. 2 9 Analysis Objectives to Design Objectives Figure 9-2

3. 3 9 Understanding the Elements of Design u Design is the process of describing, organizing, and structuring the components of a system at both the architectural level and at a detailed level l Focused on construction l Like developing blueprints u Three questions l What components require systems design? l What are the inputs to and outputs of the design process? l How is systems design done?

4. 4 9 Inputs and Outputs: Moving from Analysis to Design u Design: l Converts functional models from analysis into models that represent the solution l Focused on technical issues l Requires less user involvement than analysis

5. 5 9 SDLC Phases with Design Phase Activities Figure 9-4 Design and Integrate Network Design the Application Architecture Design the User Interfaces Design the System Interfaces Design and Integrate the Database Prototype for Design Details Design and Integrate System Controls

6. 6 9 Structured Approach to Designing the Application Architecture u Application software programs l Designed in conjunction with database and user interfaces l Hierarchy of modules u Documented with system flowcharts u Design internal program logic u Top-down approach l DFDs with automation boundaries l Structure charts

7. 7 9 Structured Design Models Figure 9-7

8. 8 9 Automation System Boundary u Partitions data flow processes into manual and automated systems u Processes can be inside or outside boundary u Data flows can be inside and outside of boundary

9. 9 9 DFD with Automation System Boundary Figure 9-8

10. 10 9 System Flowchart u Representation of various computer programs, files, databases, and associated manual processes u Graphically describes organization of subsystems u Can show type of system l Batch l Real time

11. 11 9 Common System Flow Chart Symbols Figure 9-9

12. 12 9 System Flow Chart for RMO Figure 9-11

13. 13 9 Structure Chart u Describes functions and subfunctions of each part of system u Shows relationships between modules of a computer program u Simple and direct method l Each module performs a specific function l Each layer in a program performs specific activities

14. 14 9 Structure Chart for Entire Payroll Program Figure 9-14

15. 15 9 The Create New Order DFD Fragment Figure 9-17

16. 16 9 Exploded View of Create New Order DFD Figure 9-18

17. 17 9 Rearranged Create New Order DFD Figure 9-19

18. 18 9 First Draft of the Structure Chart Figure 9-20