Defining Actors
Actors are important in requirements, as they initiate system behavior through actions (verbs). All requirements do not contain an Actor, some requirements describe system objects that have properties. Actors can be human roles, such as an Administrator, a User, a Pilot, or a Clerk. Actors can also be part of a system, such as a Parser, a Window Manager, a DHCP Server, or an LDAP Server.
The actor is defined but never used.
The Specification Author has defined an Actor that is never used by the requirements. All defined Actors need to be used at least once.
The actor is already defined.
The actor has already been defined in the Specification.