Rules for connecting shapes in Use Case Diagrams

Diagrams

Overview

Use Case Diagrams contains two shapes; Use Case and Actor. To connect these shapes, you need to use connectors available in the diagram editor. There are certain rules for connecting these shapes.

This article lists the rules to connect Use Case and Actor shapes in Use Case Diagram.

Rules to Connect Use Case and Actor Shapes

Rule 1. When you create links such as <<include>>, <<extend>>, Primary Actor and Secondary Actor between linked* Use Case and Actor shapes then this creates respective associations between linked shapes’ artifacts. You can see these associations in Non-Trace Links widget of an artifact or a Use Case Diagram.

*Linked Use Case or Actor shape means that a Use Case shape is linked to a Use Case artifact and similarly, an Actor shape is linked to an Actor artifact.

Rule 2. When you add a Use Case shape, link it to a Use Case artifact and add an Actor shape and link it to a Primary or Secondary Actor artifact, if an association already exists between the Use Case and the Actor then the link will be automatically created between them in Use Case Diagram.

NOTE

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  • Actor and System Actor shapes are allowed to link only to Actor artifact.
  • Use Case shape is only allowed to link it with Use Case artifact.
  • If you delete a line between Use Case and Actor shapes and if a corresponding association exists between the artifacts linked to the connected shapes, its association will also be deleted from the repository.

Revised: November 18th, 2021