Broader use case with admin versus casual user

Question

I have a user that manages files and an administrator that can also manage files. However the admin can manage all files whereas the user can only manage their own files. How to distinguish these in the diagram ?

Answer 1

Idea: Admin inherits from User, "Manage files with rights" inherits from "Manage files". Here's the image:

I made the UML-compliant use case model online. You can clone my public project: Use case diagram Admin User. Open the use case diagram in the tree on the left. (more information about the tool: uml online)

Answer 2

Along the lines of dupre's response, you can have 2 use cases: "manage personal files" and "manage other's files". The latter could be connected to the former with an <> stereotype and the admin user can be connected to that use case.

Answer 3

I'd say these are two distinct use cases (Manage Own and Manage Other's), but that the administrator actor is a specialization of the regular user. Thus:

This way, a person who happens to be an administrator can manage their own files by dint of being a regular user. This is actually a shorthand for "a person may fulfill the role of administrator", but unless the emphasis in the analysis is on access rights management specifically this is probably an acceptable simplification.