Reputation: 2756
In my system, a user can have more than one role. Users with two roles or more can switch between roles. However, it's impossible to switch role for a user with only one role. How can I represent this fact in use case diagram?
Thank you.
Upvotes: 4
Views: 5386
Reputation: 13711
You shouldn't show that condition in the use case diagram. The use case diagram is meant to give you a helicopter view of the features of the application and hide all the details.
You can put the condition in the pre-condition of the use case. So if you put User must have more then one role as pre-condition then the use case doesn't even start if that condition is not true.
PS. I'm assuming that your Role
is a different concept from the roles represented by the actors and that Role
could have been Account
or Group
or something else.
Upvotes: 3
Reputation: 36305
You don't. The actor represents a role he plays. And whether users can take certain roles is an organizational question. You might show a diagram with actors instances where you describe those organizational constraints.
You can use Generalization to show that there's a role hierarchy.
Upvotes: 2