In order to factor a common behaviour between a given set of activities, there is sometimes a need to link a single activity diagram with several composite activities in Enterprise Architect. As a result a double click on any of those composite activities will open the same shared diagram. The benefit is to update a single activity diagram and its elements instead of updating the details of each composite activity's diagram.
Prior to the current Sparx Enterprise Architect version (10), this could be achieved through a fastidious process.
Since version 10, EA lets you choose an existing and potentially shared/common diagram for a composite activity :
- either via a right click on the activity from the Project Browser > Add > Select Composite Diagram,
- or via a right click on the current diagram > New Diagram > Select Composite Diagram.
-> the pop-up window lets you choose an existing diagram from your EA project to set against the selected composite activity, as illustrated on the following screenshot.
Of course this hint can be applied to any other UML or SysML element such as use cases, states, etc.