| SE450: Use Cases [12/18] |
Use Cases exist to capture the intended behavior of a system without having to specify how the behavior is implemented. They are very good for specifying user requirements, and for developing good user acceptance tests
Example: p 45-46
Scenario: a sequence of steps describing an interaction between a user and the software system.
Use Case: a set of scenarios that meet a common user goal. Each use case has a name as well.
Use cases are written out as a series of Main Success Scenarios (Main flow of events), and a set of alternative Scenarios (Exceptional flow of events)
Use cases describe what not how
Use cases can be diagrammed using UML. They consist of actors (users of the system) and the use cases that they interact with. The actors carry out the use case.
Use cases can use inclusion and extension. Both of these cases help you save time writing and diagramming. This is similar to generalization, but it limits the generalization to only certain extension points. It is a special case.
For use cases c1 and c2