CSCI928 Software Engineering Requirements & Specifications Modeling System Interactions

1. CSCI928Software Engineering Requirements & SpecificationsModeling System Interactions Tri A. Kurniawan, M.Eng. Ph.D Candidate tak976@uow.edu.au

2. Agenda • Introduction • Early-phase of Requirements Engineering • Late-phase of Requirements Engineering • Deriving Use Case from Organizational Modeling CSCI928 Modeling System Interactions

3. Goal and Phases • Goal  capturing system functional requirements represented in a certain software modeling language (e.g. UML : UC diagram, sequence diagram, statechart diagram, etc.) • Requirement engineering phases : • Early-phase : problem domain understanding (organizational modeling e.g. i*, business process modeling e.g. BPMN)  less attention • Late-phase : produce a deliverable requirements document including software modeling e.g. UML CSCI928 Modeling System Interactions

4. Agenda • Introduction • Early-phase of Requirements Engineering • Late-phase of Requirements Engineering • Deriving Use Case from Organizational Modeling CSCI928 Modeling System Interactions

5. i* : Strategic Dependency Model - SD [Meeting scheduler : Victor F. A. S. and Jaelson F. B. C.] CSCI928 Modeling System Interactions

6. i* : Rationale Dependency Model - RD [Meeting scheduler : Victor F. A. S. and Jaelson F. B. C.] CSCI928 Modeling System Interactions

7. BPMN Process Modeling • R1, R2, R3, R4, R5 for Sales Staff, Workshop Staff, Sales Manager, Workshop Manager, and General Manager respectively CSCI928 Modeling System Interactions

8. Process Abstraction • Process for reducing the undesired details from the base model in order to retain only information relevant for a particular task • Example : abstraction for R3 – Sales Manager CSCI928 Modeling System Interactions

9. Agenda • Introduction • Early-phase of Requirements Engineering • Late-phase of Requirements Engineering • Deriving Use Case from Organizational Modeling CSCI928 Modeling System Interactions

10. UML Modeling • Unified Modeling Language (UML) is a standardized general-purpose modeling language in the field of software engineering • Most useful interaction diagrams : use case diagram, sequence diagram CSCI928 Modeling System Interactions

11. Use Case Diagram • The main purpose  to help development teams visualize the functional requirements of a system, including the relationship of "actors" to essential processes, as well as the relationships among different use cases • Elements : actor, use case, relationship • Actor : anything that needs to interact with the system (person, role, another system) • Use case : a sequence of related actions performed by an actor and the system via a dialogue • Relationships : actor (generalization), use case (generalization, extend, include) CSCI928 Modeling System Interactions

12. UC Diagram Example CSCI928 Modeling System Interactions

13. UC Relationships Use Case Relationships Actor Relationship CSCI928 Modeling System Interactions

14. Use Case Scenario • Describe what the system must provide to the actor when the use case is executed • Typical contents : • Name and brief description • Pre-condition and post-condition • Normal flow • Alternate flow • Special requirements CSCI928 Modeling System Interactions

15. Sequence Diagram • It shows how processes operate with one another and in what order • Sequence diagrams show step-by-step what’s involved in a use case • You may need several sequence diagrams to describe a single use case  each sequence diagram describes one possible scenario for the use case • Elements : object, stimulus (message) CSCI928 Modeling System Interactions

16. Sequence Diagram Example CSCI928 Modeling System Interactions

17. Agenda • Introduction • Early-phase of Requirements Engineering • Late-phase of Requirements Engineering • Deriving Use Case from Organizational Modeling CSCI928 Modeling System Interactions

18. Steps Goal-Oriented Analysis 1. Discovering actors 2. Discovering use case for the actors 3. Discovering and describing scenarios of use case Strategic Dependency (SD) models developed through i* framework Strategic Rationale (SR) models developed through i* framework Use case diagrams and textual description of scenarios [Meeting scheduler : Victor F. A. S. and Jaelson F. B. C.] CSCI928 Modeling System Interactions

19. Guidelines • Step 1: • Every actor in i*  UC actor • IS-A actor in i*  UC actor generalization • Actor in i*  UC external actor • Step 2: • All of actor’s (dependee) dependencies (goals, tasks, softgoal, resources)  relating use case • Step 3: • Analyze each actor and its relationships in the SR model to extract information that can lead to the description of the UC scenario for the actor CSCI928 Modeling System Interactions

20. Example : SD [Meeting scheduler : Victor F. A. S. and Jaelson F. B. C.] CSCI928 Modeling System Interactions

21. Example : SR [Meeting scheduler : Victor F. A. S. and Jaelson F. B. C.] CSCI928 Modeling System Interactions

22. Example : Result [Meeting scheduler : Victor F. A. S. and Jaelson F. B. C.] CSCI928 Modeling System Interactions

23. Exercise [Meeting scheduler : Eric S.K.Y.] CSCI928 Modeling System Interactions