Creating a Generalization Relationship
Use cases or actors can be linked with each other via generalizations. In the process, they inherit both the properties and the relationships.
Creating a Generalization Relationship Between Use Cases
Prerequisites
At least one relationship template for generalizations needs to exist in the model to be able to create a generalization relationship.
Context
You can create generalization relationships between use cases in the use case diagram.
Use cases can inherit from each other. The sub use case contains the super use case's entire behavior and can also contain other activities. Please note that relationships to actors can also be inherited as well as the behavior.
Note
A generalization relationship is always created from a special source element to the general target element; its behavior and relationships to actors are inherited.
However, it is possible to select generalizations in the diagram and reverse them with the Revert Direction context menu command and make them into the source element's specialization relationship.
How to proceed
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Select a use case in the diagram.
The carousel appears.
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Move the mouse pointer over the
Generalization connection type in the carousel. -
Drag the link with the mouse button pressed to the existing target element and release the mouse button to create a generalization relationship to an existing use case.
You have created a generalization relationship between the special use case (source) and the general use case (target).
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If you want to create a generalization relationship to a new use case instead, drag the link with the mouse button pressed to the free target position and release the mouse button.
The Create Connection dialog appears.
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Select the use case.
A general use case and the generalization relationship to the special source element are inserted in the diagram. The use case is integrated into the model structure. A unique name is created and selected.
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Enter the use case's name and then press the [Enter] key.
The use case is renamed. An error message appears if the name entered is not unique.
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If you reverse the generalization relationship and want to change it into a specialization relationship, then select the generalization relationship and select Revert Direction in the context menu.
The direction of the generalization relationship is reversed.
Creating a Generalization Relationship Between Actors
Prerequisites
At least one relationship template for generalizations needs to exist in the model to be able to create a generalization relationship.
Context
You can create generalization relationships between actors in the use case diagram. Actors inherit both the use cases' properties and relationships.
Note
A generalization relationship is always created from a special source element to the general target element; its properties and relationships to use cases.are inherited
However, it is possible to select generalizations in the diagram and reverse them with the Revert Direction context menu command and make them into the source element's specialization relationship.
How to proceed
-
Select an actor in the diagram.
The carousel appears.
-
Move the mouse pointer over the
Generalization connection type. -
Drag the link with the mouse button pressed to the existing target element and release the mouse button to create a generalization relationship to an existing actor.
You have created a generalization relationship between the special actor (source) and the general actor (target).
-
If you want to create a generalization relationship to a new actor instead, drag the link with the mouse button pressed to the free target position and release the mouse button.
The Create Connection dialog appears.
-
Select the actor.
A general actor and the generalization relationship to the special source element are inserted in the diagram. The actor is integrated into the model structure. A unique name is created and selected.
-
Enter the actor's name and then press the [Enter] key.
The actor is renamed. An error message appears if the name entered is not unique.
-
If you reverse the generalization relationship and want to change it into a specialization relationship, then select the generalization relationship and select Revert Direction in the context menu.
The direction of the generalization relationship is reversed.
