Interaction Overview Diagram
A variant of an activity diagram which overviews the control flow within a system or business process. Each node/activity within the diagram can represent another interaction diagram. The nodes within the diagram are frames instead of the normal activities which you would see on an activity diagram. There are two types of frame shown: interaction frames which depict any type of UML interaction diagram (sequence diagram, communication diagram, timing diagram, interaction overview diagram) or interaction occurrence frames which indicate an activity or operation to invoke. The other notation used on the diagram should be familiar to you. Decision points are shown as diamonds, exactly on UML activity diagrams.
The detailed processing behind the fragments is represented by the following fragments: