Creating an Association Between Actor and Use Case

Actors can be linked with use cases via associations. Use cases can be linked with multiple actors via associations.

Prerequisites

At least one relationship template for associations needs to exist in the model to be able to create an association.

Context

The actor has a relationship - not initially specified - to the use case. This association is depicted by a line between the actor and use case.

You can create an association between an actor and a new or existing use case in the diagram using the mouse. You can create the association between existing elements starting at both sides.

Note

The UML does not say which type a relationship between actor and use case is from. However, it is conventional for actors which initiate a use case to be displayed to the left of the use cases. Whereas, actors which are affected in any way by a use case are depicted to the right of the use cases.

How to proceed

  1. Select the association's source element in the diagram; this is either an actor or a use case.

    The carousel appears.

  2. Move the mouse pointer over the connection type (association).

  3. Drag the link with the mouse button pressed to the existing target element and release the mouse button to create an association to an existing element.

    You have created an association between an actor and a use case.

  4. If you want to create an association to a new element instead, drag the link with the mouse button pressed to the free target position and release the mouse button.

    The Create Connection dialog appears.

  5. Select the element type for the new diagram element.

    An element of the selected type and the association to the source element are created. The element is integrated into the model structure. A unique name is created and selected.

  6. Enter the name of the element and then press the [Enter] key.

    The diagram element is renamed. An error message appears if the name entered is not unique.