Actor (UML)

Generalization between an actor Mitarbeiterand an actorKundenberater

Example of a class Mobilfunkbetreiberthat serves as a subject for two use cases ( SMS verschickenand Fotomessage verschicken). One actor each Senderand Empfängeris involved in both use cases.

An actor ( Actor , "doer") is a model element in the Unified Modeling Language (UML), a modeling language for software and other systems.

In UML, an actor refers to an element that interacts with the modeled system. Most of the time, it is related to a use case : it is the actor who initiates a use case or who receives the expected results of a use case. Actors should not be confused with specific acting persons or systems, but rather viewed as a kind of role. Customer advisor , for example, is a better name for an actor than Mr. Meier from sales .

Because actors are a kind of classifier , they can enter into generalization relationships with one another . An example of this can be seen in the figure which shows the relationship between employees and customer advisors.

• Actors can be represented graphically in different ways
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  An actor as a "stick figure"

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  An actor as a rectangle with the keyword (stereotype) actor

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  An actor represented by a special symbol