How to represent different roles of users in UML Use cases diagrams?

Question

Imagine I have a research support application where the users can Log In with different roles like Manager , Researcher , CommiitteeCLR . Each one access different parts of the system:

Manager access user manager, add new project and project feedback(if the project is approved or not) of all committees

Researcher access only list of Projects and add new project

Committe CLR (commiittee of learning and research )access only project feedback of CLR (not all like manager)

How could I represent actors and use cases in a Use Case Diagram?

Answer 1

Each of those are actors (Manager, Researcher, etc.). Actor and role can be used as synonyms. You describe use cases per role/actor.

You can generalize actors which can come handy in some cases (where an actor inherited the general actor's use cases).

If you have some general use case and restriction per role you need to add constraints that can be attached to the association or as pre-condition to the use case itself.