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umluse-case-diagram

Dependency in Use Case Diagrams

I'm working on a high-level Use Case Diagram for a business system and want to express a relationship between 2 separate Use Cases, as follows:

  1. Actor1 performs UseCase1
  2. Actor2 performs UseCase2
  3. But the results of UseCase2 are in someway affected by UseCase1.

Is it correct to represent this relationship as a dependency, UseCase2 ---> UseCase1?

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Solution

  • There is nothing in the norm about that, so it is not possible to understand the role of the dependency looking at your diagram.

    It is very common for an UC to affect the system so to have consequences on other UCs execution, and we don't try to show that (look at How to draw a use case diagram when an actor can change the other actor's use cases?

    Of course if you really want you can add a profile&stereotype for instance <<affect>> and use it for your dependency, with associated explanations. But if you start to do that you will have a lot the dependencies <<affect>> in your diagrams and they will be unreadable.

    The right way is to not only do diagrams but also to add textual descriptions explaining the goal/effects of each UC (and of course actors) more possible pre/post conditions etc