Logical Modeling for Information System Requirements

1. Systems Analysis ProjectDeliverable 3Requirements Models

2. Deliverable 3 Context • You have defined your problem and built a set of activity diagrams that outline what the new/modified information system needs to do. • You have defined key functional and non-functional requirements • Its time to logically model the requirements from an event and object perspective.

3. Objectives • Your team’s objectives are to: • Develop an Event Table modeling 4-6 key events the system must respond to. • Develop a Class diagram that models the objects required to support your events • Develop a Functional Decomposition Diagram • Draw a context diagram for each sub-system • Draw DFD fragments for each sub-system and combine all the DFD fragments • Draw a Decision Table for Decision situation

4. Deliverable • A Word document • 11 point Arial font • Double spaced – 1.25 inch margin top and bottom. 1 inch left and right. • Good document format – same as previous deliverables • Your audience: your sponsor and the user(s) you interviewed to define requirements. Your models will also be used by designers to develop physical design documents, but this is a secondary consideration.

5. Grading • Document structure and grammar – 10% For the proposed system • Event table– 15% • Class Diagram/descriptions – 20% • Functional Decomposition Diagram (3 level hierarchy) – 10% • Context diagram for each sub-system (minimum three sub-systems) – 15% • DFD Fragments for each sub-system and combining all the fragments for a sub-system – 20% • Decision Table for one decision situation – 10%

6. Document Contents • Introduction (couple of paragraphs) • What’s in this document • Background (1/2 page – 1 page) • No more than a page – tell reader what has happened to get to this point in the project Remember to Introduce each section of your document – tell the reader what to expect!! When presenting a model, describe what the symbols mean!

7. Document Contents • Event Table. • 4-6 Events – corresponds to the business processes you modeled using activity diagrams in deliverable 2 • Use the Event Table • Make sure you introduce the section – describe what is in the table!

8. Information about Each Event in an Event Table: Catalog of Information about Each Use Case(Figure 5-15)

9. Document Contents • Class Diagram • Part 1: Diagram. • Must have at least 6 classes in your model. • At least 1 class must be associative (resolves a many to many relationship) • At least 1 class must store information about an event or transaction • Label each relationship in two directions • No many to many relationships! • Use class cardinality notation from text • Part 2: Class Descriptions. For each class provide: • Description for each class (what information does the class contain?) • Primary Key. • A minimum of 4 non-key attributes

10. Example:Course Enrollment Design Class Diagram (Figure 5-40)

11. Document Contents Use a table like the following to document each class

12. Functional Decomposition Diagram (FDD) • Draw an FDD for three levels • Level 1: Proposed System • Level 2: Sub-systems (minimum three) • Level 3: Modules (Sub-sub-systems- minimum three • modules for each sub-system )

13. Develop Context Diagram for each sub-system (minimum of 3 sub-systems)RMO Order-Entry Subsystem (Figure 6-11)

14. Three Separate DFD Fragments for Course Registration System

15. Combining DFD Fragments to Create Event- Partitioned System Model(Figure 6-8)

16. Decision Table • Draw a decision table for one decision-situation • Summarize complex decision logic • Incorporate logic into the table to make descriptions more readable

17. Reminders • Start NOW – there is a large amount of work in this deliverable. • Divide and Conquer! You will struggle if you don’t do this successfully. Suggest that you: • Meet initially to divide work and come up with a plan – when wil you meet to review and consolidate • Go off and work individually on your piece of the project • Meet to review, as required. • Have a final meeting to consolidate. • Assign one person to be responsible for final document edits – document should read as if written by one person!! This means you may decide to give one group member less modeling work – document consolidation is time consuming. • Each team member should read the consolidated document, suggest revisions, before handing the document in.