Use case design, package include use case

Question

I want to use package to group similar use cases. There is a problem about the included login use case, it make the graph not well presented. If I include the login use case in every package, I think it's wrong. Should I remove the login use case or remain?

Answer 1

Create another package "Common things" or "Support" or something like that and put "Login" and eventually other reusable use cases there. You will probably have some more commonly used use cases (like "Print report", "Logout", etc).

Than make all other packages dependent on that one:

This is a common practice of keeping your use cases nicely organized.

In this particular case of "login" I would recommend you not to "include" it in other use cases, but rather to keep it isolated and put the precondition ("User has been logged on to system") in all other use cases. This makes your model much cleaner and easier to follow, keeps the dependency and relationships count low, etc. Just imagine your diagram without this "includes" - looks better, right? :)

If you decide to do it this way, keep the same packages I suggested, but remove the dependencies (as the "login" is not included any more), unless there are other included/extended UCs that justify the dependency.

Answer 2

Login is not a UseCase at level of detail you presented in the diagram. Just remove Login Usecase and your diagram will be correct. By usecase definition in UML. UseCase represents usefull functionality of system. Login is not a functionality from this point of view, but it is precondition to execute usecases you defined. It means, user must be logged on in order to interract with system within UseCase eecution.