Completion events and transitions

Completion events are standard UML events which are fired during the execution of a state machine diagram.

For composite or submachine states, a completion event is generated under the following circumstances:

• When all internal activities (e.g., entry and doActivity Behaviors) have completed execution, and
• If the State is a composite State, all its orthogonal Regions have reached a FinalState, or
• if the State is a submachine State, the submachine StateMachine execution has reached a FinalState.
   

Figure 1: Completion events and transitions environment value

Case 1:

Figure 2: Completion events and Transitions in a state machine diagram

For example, in the above state machine diagram, a transition from the "on" state to the "off" state does not happen until a completion event is generated. The completion event is generated after the DoActivity behavior completes and only then the state transits from "on" to "off".

Case 2:

Figure 3: Completion Events and Transitions in a state machine diagram

In the above state machine diagram, a completion event is generated after the entry and sendOff behaviors have completed.

Case 3:

Figure 4: Completion Events and Transitions in a state machine diagram

In the above state machine diagram, a completion event will be generated after the entry and working behaviors have completed.