You can create an interaction activity from the Toolbox or Browser.
Use the Interaction Activity tool in the Toolbox.
The Select a diagram dialog box opens to allow you to specify the diagram to which the activity refers. Select an existing or new diagram and click OK.
Drag a sequence, communication or interaction overview diagram from the browser and drop it into an interaction overview diagram.
For general information about creating objects, see Core Features Guide > The PowerDesigner Interface > Objects.