To create a part element, choose one of the following methods.
Using the diagram toolbar button:
Click the Part button
on the diagram toolbar.
Click on the diagram to create the element.
Using the diagram context menu:
In Diagram view, right click on the background.
From the context menu, select New > Part.
Using the element context menu:
In the UML Navigator view, right click on the collaboration2.0 diagram.
From the context menu, select New > Part.