1. CSCI928 Software Engineering Requirements & Specifications Modeling System Interactions Tri A. Kurniawan, M.Eng. Ph.D Candidate tak976@uow.edu.au

2. CSCI928 Modeling System Interactions2/23 Agenda ▶ Introduction ▶ Early-phase of Requirements Engineering ▶ Late-phase of Requirements Engineering ▶ Deriving Use Case from Organizational Modeling

3. CSCI928 Modeling System Interactions3/23 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

4. CSCI928 Modeling System Interactions4/23 Agenda ▶ Introduction ▶ Early-phase of Requirements Engineering ▶ Late-phase of Requirements Engineering ▶ Deriving Use Case from Organizational Modeling

5. CSCI928 Modeling System Interactions5/23 i* : Strategic Dependency Model - SD [Meeting scheduler : Victor F. A. S. and Jaelson F. B. C.]

6. CSCI928 Modeling System Interactions6/23 i* : Rationale Dependency Model - RD [Meeting scheduler : Victor F. A. S. and Jaelson F. B. C.]

7. CSCI928 Modeling System Interactions7/23 BPMN Process Modeling ▶ R1, R2, R3, R4, R5 for Sales Staff, Workshop Staff, Sales Manager, Workshop Manager, and General Manager respectively

8. CSCI928 Modeling System Interactions8/23 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

9. CSCI928 Modeling System Interactions9/23 Agenda ▶ Introduction ▶ Early-phase of Requirements Engineering ▶ Late-phase of Requirements Engineering ▶ Deriving Use Case from Organizational Modeling

10. CSCI928 Modeling System Interactions10/23 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

11. CSCI928 Modeling System Interactions11/23 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)

12. CSCI928 Modeling System Interactions12/23 UC Diagram Example

13. CSCI928 Modeling System Interactions13/23 UC Relationships Actor Relationship Use Case Relationships

14. CSCI928 Modeling System Interactions14/23 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

15. CSCI928 Modeling System Interactions15/23 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)

16. CSCI928 Modeling System Interactions16/23 Sequence Diagram Example

17. CSCI928 Modeling System Interactions17/23 Agenda ▶ Introduction ▶ Early-phase of Requirements Engineering ▶ Late-phase of Requirements Engineering ▶ Deriving Use Case from Organizational Modeling

18. CSCI928 Modeling System Interactions18/23 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.]

19. CSCI928 Modeling System Interactions19/23 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

20. CSCI928 Modeling System Interactions20/23 Example : SD [Meeting scheduler : Victor F. A. S. and Jaelson F. B. C.]

21. CSCI928 Modeling System Interactions21/23 Example : SR [Meeting scheduler : Victor F. A. S. and Jaelson F. B. C.]

22. CSCI928 Modeling System Interactions22/23 Example : Result [Meeting scheduler : Victor F. A. S. and Jaelson F. B. C.]

23. CSCI928 Modeling System Interactions23/23 Exercise [Meeting scheduler : Eric S.K.Y.]