Different Stakeholders use this artifact for different purposes:

• Analysts use this artifact to define the system boundaries, identify external interfaces, and describe Use Cases interactions with Actors.
• Developers use this artifact to capture characteristics of human Actors when they are creating the user interface and to realize Use Cases (in terms of objects) and their interaction with Actors.

• Analyst

• Analyst

• Detail Requirements
• Find and Outline Requirements

To fully understand the system's purpose, you must know who the system is for, that is: Who will use the system? Actors represent different types of users. An actor is anyone or anything that exchanges data with the system. Therefore, an actor can be a user, external hardware, or another system.

The difference between an actor and an individual system user is that an actor represents a particular class of users, rather than an actual user. Several users can play the same role, which means that they can be the same, single actor. In that case, each individual user constitutes an instance of the actor.

As an illustration, Ivar and Mark are operators of a recycling machine. When they are using the machine, each is represented by an instance of the actor called Operator.

However, in some situations, only one person plays the role modeled by an actor. For example, there may be only one individual in the role of system administrator for a rather small system.

The same user can also act as several actors (that is, the same person can take on different roles).

Charlie uses the Depot-Handling System primarily as Depot Manager, but sometimes he also uses the Depot-Handling System as an ordinary Depot Staff member.

For each Actor identified, document the name and brief description.

It is also necessary to capture the Use Cases that this Actor initiates and those in which the Actor plays a secondary role.

If your project is using a Use Case model, there is no need for a separate representation for Actors other than in the Use Case model and in the Use Case specification.

The simplest method is to capture the Actor's name and a its brief description in a table. Include a list of the Use Cases that this Actor initiates, as well as the Use Cases in which the actor participates in a secondary role. See the discussion of the Actor-Goal-List in Guideline: Use Case Formats for more information on this representation option.

• Actor

• Find and Outline Actors and Use Cases
• Use Case Formats