Stimulate 2005 Instructor: Luz M. Quiroga University of Hawaii Information and Computer Science / Library and information Science POST 314b; System Analysis and Design (SA&D) Object Oriented modeling Part 2: Use case modeling

Object Orientation Application to system analysis (Osborne, Sinha)

Use Case Modeling Applied to analyze functional requirements of the system Performed during the analysis phase to help developers understand functional requirements of the system without regard for implementation details Use Case –A complete sequence of related actions initiated by an actor Actor –An external entity that interacts with the system

Use Case Modeling Use cases are always initiated by an actor Use cases represent complete functionality of the system Use cases may participate in relationships with other use-cases Use cases may also use other use cases

Use-case Modeling (Fig. A1 - Source: Sinha) A use case consist of actors (stick figure) and use case (oval) It represent the typical interactions user - systems Several relationships used to explain how a use case is related to use cases and uses: association / extend / include

Use-case Modeling (Fig. A1- Source: Sinha) Association: communication between actor and use case Example: Student using class registration Depicted as a line ; typically represents two way communication between the use case and the actor, then no arrowheads needed (if only one way then use solid arrowhead)

Use-case Modeling (Fig. A1- Source: Sinha) A use case may participate with other uses cases: extend relationship (hollow triangle toward the extended case; > label) Class registration is always performed; the extension: e.g. registration for special classes is performed only under special circumstances

Use-case Modeling (Fig. A1- Source: Sinha) Another kind of relationship is “include”, labeled > It implies that one cases uses another while executing (aggregation; part – whole; functional decomposition) When a manager reorder supplies, the sales and inventory data are tracked.

Use case exercise: Valacich app. A (author of the chapter: Sinha) Exercise 2. p. 422; reference to figure A1 of previous slides Suppose that the employees of the university are not billed by tuition. Their spouse do not get a full tuition waiver, but pay for only 25 % of the total tuition. Extend the use-case diagram of fig. A-1 to capture these situations Draw the diagram with MS- Visio