Interaction overview diagram

Interaction Overview Diagram[1] is one of the fourteen "nominative" types of diagrams[2] of the Unified Modeling Language (UML), which can picture a control flow with nodes that can contain interaction diagrams.

The interaction overview diagram is similar to the activity diagram, in that both visualize a sequence of activities.

The difference is that, for an interaction overview, each individual activity is pictured as a frame which can contain a nested interaction diagram.

This makes the interaction overview diagram useful to "deconstruct a complex scenario that would otherwise require multiple if-then-else paths to be illustrated as a single sequence diagram".

These include initial, final, decision, merge, fork and join nodes.