1. PowerPoint Presentation by Charlie Cook Copyright © 2004 South-Western. All rights reserved. Lecture 3 Documenting Business Processes and Information Systems Documenting Business Processes and Information Systems

2. Copyright © 2004 South-Western. All rights reserved.2–2 Data Flow Diagrams (DFD) Context diagram  Top-level diagram Physical flow diagram  Internal entity  External entity Logical data flow diagram  Process and flow of data Systems flow charts  Information processes and operations processes

3. Copyright © 2004 South-Western. All rights reserved.2–3 Data Flow Diagram (DFD) Symbols FIGURE 2.1 NOTES: a. A bubble can be either an entity on a physical data flow diagram or a process on a logical data flow diagram. b. The data store symbol may represent a view—a portion—of a larger entity-wide database.

4. Copyright © 2004 South-Western. All rights reserved.2–4 A Context Diagram FIGURE 2.2

5. Copyright © 2004 South-Western. All rights reserved.2–5 A Physical Data Flow Diagram FIGURE 2.3

6. Copyright © 2004 South-Western. All rights reserved.2–6 A Logical Data Flow Diagram (Level 0 Diagram) FIGURE 2.4

7. Copyright © 2004 South-Western. All rights reserved.2–7 Balanced Data Flow Diagrams The next five slides depict “balanced” data flow diagrams. Balanced DFDs exist when the external data flows are equivalent. The first DFD is a context diagram and the next one is an “explosion” of it into a level 0 logical DFD. The next diagram is an “explosion” of the logical level 0 DFD, and so on.

8. Copyright © 2004 South-Western. All rights reserved.2–8 A Set of Balanced DFDs FIGURE 2.5a

9. Copyright © 2004 South-Western. All rights reserved.2–9 A Set of Balanced DFDs (cont’d) FIGURE 2.5b

10. Copyright © 2004 South-Western. All rights reserved.2–10 A Set of Balanced DFDs (cont’d) FIGURE 2.5c NOTES: 1. There is no Diagram 2.0, as process 2.0 is an elementary process (i.e., it cannot be exploded further). 2. Assume that bubbles 1.1, 1.2, 1.3, 1.4, 3.1.1, 3.1.2, and 3.2 are elementary processes.

11. Copyright © 2004 South-Western. All rights reserved.2–11 Systems Flowcharting Symbols FIGURE 2.6a

12. Copyright © 2004 South-Western. All rights reserved.2–12 Systems Flowcharting Symbols (cont’d) FIGURE 2.6b

13. Copyright © 2004 South-Western. All rights reserved.2–13 Common System Flowcharting Routines The following slides show several common ways of showing processing using system flowcharting. Pay particular attention to the way the columns are set up to communicate the flow of activities between processing entities.

14. Copyright © 2004 South-Western. All rights reserved.2–14 FIGURE 2.7a (a) Enter document into computer via keyboard, edit input, record input Common Systems Flowcharting Routines (c) Update sequential data store

15. Copyright © 2004 South-Western. All rights reserved.2–15 FIGURE 2.7b Common Systems Flowcharting Routines (cont’d) (d)Preparation and later manual reconciliation of control totals

16. Copyright © 2004 South-Western. All rights reserved.2–16 FIGURE 2.7c Common Systems Flowcharting Routines (cont’d) (e) Key and key verify inputs

17. Copyright © 2004 South-Western. All rights reserved.2–17 FIGURE 2.7d Common Systems Flowcharting Routines (cont’d) (e) Key and key verify inputs (f) Enter document into computer using scanner (g) Enter document into computer using scanner and manual keying

18. Copyright © 2004 South-Western. All rights reserved.2–18 Causeway Context Diagram FIGURE 2.10

19. Copyright © 2004 South-Western. All rights reserved.2–19 Causeway Current Physical DFD FIGURE 2.11

20. Copyright © 2004 South-Western. All rights reserved.2–20 Table of Entities and Activities for Causeway Cash Receipts System (Annotated) TABLE 2.2

21. Copyright © 2004 South-Western. All rights reserved.2–21 Causeway Current Logical DFD (Level 0) FIGURE 2.12

22. Copyright © 2004 South-Western. All rights reserved.2–22 Drawing DFD Diagrams The basic steps of the process are:  Create or obtain an accurate and reliable narrative.  From the narrative, create a complete table of entities and activities.  Draw a context diagram with external entity boxes by distinguishing carefully between internal and external entities.  Draw current physical flow diagrams by creating bubbles for internal entities, and showing flows to and from all entities and data stores.  Draw current logical flow diagrams by grouping activities that occur together, and naming the logical sub-processes each describes.

23. Copyright © 2004 South-Western. All rights reserved.2–23 Causeway Systems Flowchart FIGURE 2.13

24. Copyright © 2004 South-Western. All rights reserved.2–24 Physical DFD for Problem 2-1 FIGURE 2.14

25. Copyright © 2004 South-Western. All rights reserved.2–25 Logical DFD for Problem 2-2 FIGURE 2.15