OV-6b is a graphical method used to describe how an operational node or activity responds to various events while changing its state. The associated diagram shows the sets of events to which the architecture will respond (by taking an action to move to a new state) as a function of its current state. Each transition specifies an event and an action.

The MEGA Suite for DoDAF 2 is used to describe the specific behaviors (state machines) attached to activities. A behavior is a specific concept used to describe how an activity reacts to different events from start points to end points.