Checklist: Actor
This check list provides questions to help ensure that all actors, and only valid actors, have been identified and described correctly.
Relationships
Check Items
Have you found all the actors
Have you accounted for all roles in the systems environment?  See Guideline: Find and Outline Actors and Use Cases for some questions that may help identify actors.
Is each actor involved with at least one use case
If you cannot identify a use case associated with a given actor perhaps the actor should be removed, or perhaps you are missing a use case.
Can you identify at least two people, or external systems, that would play the role of a particular actor
If you cannot, check if the role that the actor represents is part of another actor.  If that is the case, you should merge the actors.
Will a particular actor use the system in several completely different ways

If true, you should probably have more than one actor.

Does the actor have several completely different purposes for using the system
If true, there may be more than one actor.
Have you considered maintenance and administrative roles
It is common to focus on the daily users of the system, and forget about administrative and maintenance roles such as setting up user accounts, managing access rights, performing backups, etc.  Ensure you have captured these actors.
Does each actor have a clear description of its role
Each actor should have a short description of the role and the main goal the actor has in using the system.