Actors correspond to the different types or levels of users who are required to use an application.

When different actors share certain common prerogatives, an inheritance system makes it possible to specify that actor A can perform the same actions as actor B in addition to its own.

Actor diagram #

The actor diagram provides a visual representation of the relationships and inheritances between the different actors of the system.

The example below can be read as follows:

• The reference actor is named User: it is to this actor that basic Features such as Log in, Log out, and Reset password are linked; it is also to this actor that the attributes indicating that he has an Identifier, a Password, a Last Name, and a First Name are attached.
• All actors directly or indirectly related to the User actor have at least the same prerogatives and the same attributes: they are said to inherit the characteristics of the User actor.
• The diagram indicates that the Referent and Client actors inherit from User: they have the same attributes (Identifier, Password…) as User, plus others that are specific to them.
• The diagram also indicates that the Administrator actor has his own attributes in addition to those of the Referent: by extension, he therefore has the attributes and prerogatives of the User actor.

List of actors #

The list of actors provides a table-based representation of the different actors and their inheritance relationships.

List of Use Cases #

When specifying a use case, the relevant actor is selected. This allows you to display the list of use cases for each actor, as in the example below for the « Referent » actor.

Note: it is possible to visualize the UML diagram of use cases, showing the actors involved, by displaying the details of a Feature.