1. Chapter 9 Moving to Design
Systems Analysis and Design in a Changing World, 2nd Edition, Satzinger, Jackson, & Burd

2. Objectives
Discuss the issues related to the management and coordination of the design phase of the SDLC
Develop a system flowchart
Develop a structure chart using transaction analysis and transform analysis
Systems Analysis and Design in a Changing World, 2nd Edition, Satzinger, Jackson, & Burd

3. Objectives Write pseudocode for structured modules
Develop a package diagram
Develop a design class diagram
Explain the major components and levels of design
Describe the difference between models produced by the structured design and object-oriented design
Systems Analysis and Design in a Changing World, 2nd Edition, Satzinger, Jackson, & Burd

4. Components Requiring Systems Design Figure 9-1
Systems Analysis and Design in a Changing World, 2nd Edition, Satzinger, Jackson, & Burd

5. Analysis Objectives to Design Objectives Figure 9-2
Systems Analysis and Design in a Changing World, 2nd Edition, Satzinger, Jackson, & Burd

6. Understanding the Elements of Design
Design is the process of describing, organizing, and structuring the components of a system at both the architectural level and at a detailed level
Focused on construction
Like developing blueprints
Three questions
What components require systems design?
What are the inputs to and outputs of the design process?
How is systems design done?
Systems Analysis and Design in a Changing World, 2nd Edition, Satzinger, Jackson, & Burd

7. Inputs and Outputs: Moving from Analysis to Design
Converts functional models from analysis into models that represent the solution
Focused on technical issues
Requires less user involvement than analysis
Design may use structured or OO approaches
Database can be relational, OO or hybrid
User Interface issues
Systems Analysis and Design in a Changing World, 2nd Edition, Satzinger, Jackson, & Burd

8. 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
Systems Analysis and Design in a Changing World, 2nd Edition, Satzinger, Jackson, & Burd

9. Project Coordination Project teams Information Team Communication
Project schedule
Information
CASE Tools
Team Communication
Systems Analysis and Design in a Changing World, 2nd Edition, Satzinger, Jackson, & Burd

10. Information Stored in the CASE Repository
Figure 9-6
Systems Analysis and Design in a Changing World, 2nd Edition, Satzinger, Jackson, & Burd

11. Structured Approach to Designing the Application Architecture
Application software programs
Designed in conjunction with database and user interfaces
Hierarchy of modules
Documented with system flowcharts
Design internal program logic
Top-down approach
DFDs with automation boundaries
Structure charts
Systems Analysis and Design in a Changing World, 2nd Edition, Satzinger, Jackson, & Burd

12. Structured Design Models Figure 9-7
Systems Analysis and Design in a Changing World, 2nd Edition, Satzinger, Jackson, & Burd

13. Automation System Boundary
Partitions data flow processes into manual and automated systems
Processes can be inside or outside boundary
Data flows can be inside and outside of boundary
Systems Analysis and Design in a Changing World, 2nd Edition, Satzinger, Jackson, & Burd

14. DFD with Automation System Boundary
Figure 9-8
Systems Analysis and Design in a Changing World, 2nd Edition, Satzinger, Jackson, & Burd

15. System Flowchart
Representation of various computer programs, files, databases, and associated manual processes
Graphically describes organization of subsystems
Can show type of system
Batch
Real time
Systems Analysis and Design in a Changing World, 2nd Edition, Satzinger, Jackson, & Burd

16. Common System Flow Chart Symbols
Figure 9-9
Systems Analysis and Design in a Changing World, 2nd Edition, Satzinger, Jackson, & Burd

17. System Flow Chart for RMO
Figure 9-11
Systems Analysis and Design in a Changing World, 2nd Edition, Satzinger, Jackson, & Burd

18. Structure Chart
Describes functions and subfunctions of each part of system
Shows relationships between modules of a computer program
Simple and direct method
Each module performs a specific function
Each layer in a program performs specific activities
Systems Analysis and Design in a Changing World, 2nd Edition, Satzinger, Jackson, & Burd

19. Structure Chart Symbols
Figure 9-13
Systems Analysis and Design in a Changing World, 2nd Edition, Satzinger, Jackson, & Burd

20. Entire Payroll Program
Structure Chart for
Entire Payroll Program
Figure 9-14
Systems Analysis and Design in a Changing World, 2nd Edition, Satzinger, Jackson, & Burd

21. Developing a Structure Chart
Transaction Analysis
System flow chart and event table inputs
Upper-level modules developed first
Identifies each transaction supported by program
Transform Analysis
Computer program ‘transforms’ inputs into outputs
Structure charts have input, calculate, and output subtrees
Uses DFD fragments for inputs
Systems Analysis and Design in a Changing World, 2nd Edition, Satzinger, Jackson, & Burd

22. Steps to Create a Structure Chart from a DFD Fragment
Determine primary information flow
Find process that represents most fundamental change from input to output
Redraw DFD with inputs to the left and outputs to the right
Generate first draft structure chart
Systems Analysis and Design in a Changing World, 2nd Edition, Satzinger, Jackson, & Burd

23. Steps to Create a Structure Chart from a DFD Fragment (Continued)
Add other modules
Input
Data storage
Output
Add logic from structured English or decision tables
Make final refinements
Systems Analysis and Design in a Changing World, 2nd Edition, Satzinger, Jackson, & Burd

24. The Create New Order DFD Fragment Figure 9-17
Systems Analysis and Design in a Changing World, 2nd Edition, Satzinger, Jackson, & Burd

25. Exploded View of Create New Order DFD
Figure 9-18
Systems Analysis and Design in a Changing World, 2nd Edition, Satzinger, Jackson, & Burd

26. Rearranged Create New Order DFD
Figure 9-19
Systems Analysis and Design in a Changing World, 2nd Edition, Satzinger, Jackson, & Burd

27. First Draft of the Structure Chart
Figure 9-20
Systems Analysis and Design in a Changing World, 2nd Edition, Satzinger, Jackson, & Burd

28. Quality of Structure Chart
Module coupling
Measure of how module is connected to other modules in program
Module cohesion
Measure of internal strength of module
Module performs one defined task
Highly cohesive and loosely coupled modules are desirable
Systems Analysis and Design in a Changing World, 2nd Edition, Satzinger, Jackson, & Burd

29. Module Algorithm Design: Pseudocode
Describes internal logic of software modules
Variation of structured English that is closer to programming code
Syntax should mirror development language
Systems Analysis and Design in a Changing World, 2nd Edition, Satzinger, Jackson, & Burd

30. OO Approach to Design of Application Architecture
OO analysis forms basis for OO design
Structure must support OO programming
Programs cooperate to perform tasks
No one program module is ‘in-charge’
Consists of sets of computing objects
Encapsulation and information hiding
Systems Analysis and Design in a Changing World, 2nd Edition, Satzinger, Jackson, & Burd

31. OO Analysis Models to Design Models
Figure 9-27
Systems Analysis and Design in a Changing World, 2nd Edition, Satzinger, Jackson, & Burd

32. Package diagrams Identifies major components of a system
High-level diagram in UML
Similar in function to flow chart
Determines final program partitions
Dependencies determined
Systems Analysis and Design in a Changing World, 2nd Edition, Satzinger, Jackson, & Burd

33. RMO CSS Package Diagram
Figure 9-28
Systems Analysis and Design in a Changing World, 2nd Edition, Satzinger, Jackson, & Burd

34. Design Class Diagrams Shows set of classes and their relationships
Describes design components within the classes
More complete than analysis versions of same diagrams
Systems Analysis and Design in a Changing World, 2nd Edition, Satzinger, Jackson, & Burd

35. Internal Symbols Used to Design a Design Class
Figure 9-31a
Systems Analysis and Design in a Changing World, 2nd Edition, Satzinger, Jackson, & Burd

36. Internal Symbols for Design Class
Figure 9-31b
Systems Analysis and Design in a Changing World, 2nd Edition, Satzinger, Jackson, & Burd

37. Design Class Diagram Development
Choose single class from class diagram
Elaborate the attributes
Identify methods
Elaborate methods with logic
Systems Analysis and Design in a Changing World, 2nd Edition, Satzinger, Jackson, & Burd

38. Short Form of the Order Design Class
Figure 9-34
Systems Analysis and Design in a Changing World, 2nd Edition, Satzinger, Jackson, & Burd

39. Finishing up OO Design Inheritance, overriding, and polymorphisms
Integration with user-interface design, database design, and network design
Systems Analysis and Design in a Changing World, 2nd Edition, Satzinger, Jackson, & Burd