Actor Generalization   Actor generalization is a way of factoring out commonality that exists between a number of actors. The actors must be of the same type or family, and have associations with the same set of use cases. The specialized actors may add or remove associations, and can always stand in the place of the parent or more generalized actor. The more generalized actor is often, but not always, abstract.

Explanation

Actor generalization is a relationship of family between two actors. As with all types of generalization the specialized actor inherits the behavior of the more general parent. The child actor has associations with the same set of use cases as the parents and presumably has the same goals with respect to its interaction with the entity represented by the use cases.

Important Points

A child or more specialized actor can always be substituted for a parent or more generalized actor.

This simply means that the more specialized actor, the child, is a type of the more generalized actor, the parent, and exhibits the fundamental characteristics of the family.

Related Entries

Generalization  Base Type A generalization relationship is related to an actor generalization because it is the definition of the fundamental relationship. The actor generalization is a specific example of the generalization relationship between actors in the use case model.

Use Case Generalization  Used Together Use case generalization is often used in conjunction with actor generalization. When commonality between the use cases has been factored out by using the generalization relationship it is often the case that a symmetrical generalization will exist between the actors. This is not always the case, but represents a visual pattern in the use case model that can assist in uncovering commonality that exists between elements in the model.