What are Actors?

Actors are things outside the system but interact with it. They may receive or deliver information to the system or do both. An actor is not the person that interacts with the system but the role that he or she plays.

Actors are a role of an entity or entities outside of a system that interact directly with it as part of a coherent work unit. An Actor element characterizes the role played by an outside object,where one physical object may play several roles and therefore be modelled by several Actors. For example,one entity may assume different identities and roles in various cases.

An example Actor is shown below:

Names of Actors are usually discovered from dialogue with the users or in the problem statement.

What is the Actor's role?

A brief description for each Actor,which determines the role,the actor plays when interacting with the system.