umluse-casesequence-diagram

Sequence Diagram vs Usecase Diagram


I have build a usecase diagram for hotel reservation

Should i build a sequence diagram for each usecase in the usecase diagram, or can i summarize multiple usecase in a single sequence diagram?


Solution

  • A use case diagram shows how use cases and actors relate to each other and gives a usefulness system overview. Use cases boil the system down to their added values and do not show how these are achieved.

    Any scenario of a use case is graphically represented in an activity diagram where the single steps occur as actions.

    A sequence diagram is used to show how objects communicate.

    Usually you derive classes and relate them to actions of the use case activities. So when you create a sequence diagram it highlights a certain aspect of the whole system. This highlight is usually spot on and not a floodlight. Putting multiple use case scenarios in a single SD would for sure simply blind any reader instantly.