A use case diagram shows Actors, Use Cases, and Requirements and how they're releated.
To create a use case diagram:
- Add an empty diagram: Choose which item in your project that will own the diagram, for example, you might choose to create the diagram in a package or in a use case. Right click on that item in the project browser and select Add Diagram.... Give the diagram a meaningful name .
- Drag an item (any use case, actor, or requirement) from the project browser and drop onto the diagram surface.
- Right click on the resulting shape and select Add Related Shapes/Connectors. If there are any related items they will be added to the diagram. For example, if you add related shapes for a use case, the primary and supporting actors of the use case will be added.
- Perform step 3 on other shapes in your diagram until you have populated your use case diagram to the desired extent.
- If shapes get added that you don't want in the diagram, select them and press delete. The shapes will be removed from the diagram but the item itself will still remain in the project.
- Drag other desired items from the project browser into the diagram. If they are related to existing shapes, the connectors between them will automatically be added.