Describe two techniques for identifying use cases. Which is the most comprehensive approach?

Answer 1

Two techniques for identifying use cases are the user goal technique and the event decomposition technique. The user goal technique involves identifying all actors or users of the system and asking, "What are their goals in using the system?" Goals are identified at the elementary business process (EBP) level of analysis. The event decomposition technique involves asking, "What events does the system need to respond to?" External events, temporal events, and state events are identified. The use case is what the system does to react to or respond to each event. The event table is used to catalog information about each event and the resulting use case. The event decomposition technique is the most comprehensive technique. Both techniques involve the idea of an elementary business process (EBS) being a system process in response to a business event. A third technique discussed in chapter 7 is the CRUD technique, where the analyst identifies for each domain class the create, read or report, update, and delete use cases required. In practice, multiple approaches should be used to cross check each other to assure all use cases are identified.