From Business To System Use Cases

1. From Business To System Use Cases Presented by Leslie Munday

2. Agenda/Contents • The purpose of this presentation is to give an overview of the connection between the Business Modeling, Enterprise Architecture and Requirements disciplines of the PRC Dev Case. • In the next two hours we will cover: • Business Use Cases (BUCs) • Traceability From BUCs To Stakeholder Requirements • Allocation Of Business Activities • Candidate System Use Cases (CSUCs) • Traceability From CSUCs To BUCs • System Use Cases (SUCs) • Traceability From SUCs To BUCs

3. Intended Audience • This presentation will demonstrate how AWS relates business use cases to system use cases. • At the end of this presentation you will understand how to: • allocate business activity to systems; • create a candidate system use case model; • manage traceability between BUCs and SUCs.

4. Prerequisites • In order to fully understand this presentation you should have previous experience with: • Business use case modeling. • System use case modeling. • Modeling with Rational Rose. • Managing traceability with RequisitePro.

5. Use Cases Revisited What is a Use Case • Primary actor - Initiates the use case • Secondary actors - Interfaces with the use case • Precondition - The state immediately before the use case begins • Basic flow step - A required step in the use case flow • Alternative flow step - An unexpected step in the use case flow • Postcondition(s) - A state immediately after the use case completes.

6. Types Of Use Case • Business(BUC) – Describes a story involving the interaction of people and the things they are manipulating or using. • System(SUC): • Describes a story of an interaction between an actor (could be a person or a machine) and the system being constructed. • System use cases are the result of a desire to automate parts of business use case. • Candidate System Use Case(CSUC): • An allocation of a BUC step to a SUC.

7. Rose-ReqPro Association • Associate package to project. • Disassociate package from Project.

8. Use Case–ReqPro Association • New – Create item in ReqPro. • Associate – Link to ReqPro item. • Open – Display associated ReqPro item. • Disassociate – Unlink from associated ReqPro item.

9. Use Case-ReqPro Commands • Requirement Properties →New - Creates an associated ReqPro requirement of the appropriate type (SUC or BUC). • Use Case Document →New – Creates a use case specification of the appropriate type (SUC or BUC) and creates an associated ReqPro requirement. • Requirement Properties →Associate – Links the use case to a ReqPro requirement. • Use Case Document →Associate - Links the use case to a ReqPro to a Specification. • View RequisitePro Association – Shows you which project this use case is linked to.

10. Traceability Tree • Shows how Stakeholder Requests are realized by Business Use Cases.

11. Activity Diagrams • Describe the steps in a use case, as activities connected by transitions. • Show alternate flows, as transitions leaving decision boxes. • Show parallel activities with synchronization bars. • Indicate the preconditions to the use case, as a start state. • Indicate postconditions of the use case, as end states. • Show who performs the business activities, and what systems they are allocated to by placing activities in swimlanes. • (Optionally) Defines objects that are produced and consumed by activities.

12. BUC Diagram

13. A BUC Activity Diagram

14. A System Use Case Diagram

15. What Is The Connection? • Steps in a BUC must be realized by a SUC, otherwise they are manual activities. • The SUC automates steps in a BUC in an order to reduce: • manual effort. • the risk of making mistakes. • duplication of work. • other factors (cost, speed, etc).

16. Swimlanes In Business Activity Diagrams • Swimlanes allow the activities in the BUC to be allocated to actors. • Actors may be people or systems. • Add a swimlane for each actor, worker and potential system that will perform and activity. • Place the activity in its appropriate swimlane.

17. Swimlane Example

18. Linking BUCs And SUCs • Create a requirement specification in ReqPro for the BUC. • Create a requirement in ReqPro for the SUC. • Open the properties window for the SUC and add a Trace From BUC link. OR • Open the properties window for the BUC and add Trace To SUC link. • A BUC will have many SUC links. A SUC may have many BUC links.

19. Create Requirements For Steps • Each activity in the BUC has an equivalent step in the BUC specification. • Each step in the BUC specification is associated with an equivalent requirement in the ReqPro BUC package. • Each activity is labeled with the identifier given by ReqPro to the equivalent requirement.

20. ReqPro BUC Steps

21. Activity Diagram With Identifiers

22. Traceability Report Between BUC Steps and BUC activities

23. Candidate System Use Cases • Are how we get from BUCs to SUCs in Rational Rose. • In the Candidate System Use Case Package, a CSUC exists for each activity in the BUC activity diagram. • The CSUC is given the same name as the activity (including identifier). • The CSUC is not linked to the BUC Activity, so we use a SoDA report to check consistency. • Using the trace to link in the CSUC requirement, the CSUC is linked to the actual SUCs.)

24. Business Allocation Diagram • Shows activities allocated to candidate systems

25. CSUC Diagram • Shows CSUCs Traced to the BUC

26. SoDA Report Of Rose Traceability Return Book : BUCS1.Requesting Patron Details => BUCS1.Requesting Patron Details Traceability to Return Book found. BUCS4.Changing Customer Record => BUCS4.Changing Customer Record Traceability to Return Book found. BUCS6.Filing Customer Record => CS6.Filing Customer Record Traceability to Return Book found. BUCS8.Finding Who Book Is Checked To => No Candidate System Use Case found. BUCS9.Changing Check-Out Details => BUCS9.Changing Check-Out Details No traceability link found.

27. CSUC Diagram II Shows CSUCs Traced to SUCs

28. BUC To SUC Traceability • Enter the traceability links into ReqPro

29. Traceability Tree Traceability tree showing how Stakeholder Requests are realized by System Use Cases.

30. Summary • STRs manually entered into ReqPro, or through the Vision document. • BUCs entered into Rose and attached to BUC requirements in ReqPro. • BUC specifications attached to BUC requirements in ReqPro. • BUC requirements traced from STRs in ReqPro. • BUC activities attached to BUC in Rose activity diagram. • BUC Activities traced to BUC specification using a SoDA report. • BUC activities allocated to systems in Rose BAD. • BUC traced to CSUCs using a Rose traceability diagram. • BUC activities traced to CSUCs using a SoDA report. • CSUCs traced to SUCs in Rose traceability diagram. • SUCs attached to SUC requirements in ReqPro. • SUCs trace to BUCs in ReqPro.

31. Traceability Overview