UML Modeling Techniques > Object interaction modeling > Communication diagram > Checking a communication diagram
  
Checking a communication diagram
Right-click the diagram, point to Report, and then click Consistency.
The report is generated to the Output pane.
Modeler makes the following checks:
There are items on the diagram (C1).
The number of actual parameters and formal parameters match for each message (C20004). You set actual parameters on a message's instance Property Pages.
Each Instance is stimulated by an incoming message (C20003).
There is an Operation or Event message on each link (C20002).
Each message sequence number is unique (C20006). Message sequence numbers are set on a message's instance Property Pages.