Use case to/from actor association

Association relationship are the only type of relationships that is allowed between actors and use cases.

Each use case must be associated with one or more actors. Likewise, each actor must be associated with at least one use case. There is no limitation of how many use cases can be associated with an actor, or how many actors can be associated with a use case.

Note that at this stage, it is not necessary to know how an actor is involved in a use case. Instead, a systems analyst should concentrate on enumerating all actors who can be involved in a use case.