Synchronizing sequence diagram with collaboration diagram
To synchronize a Sequence diagram with its partner Collaboration diagram, select Draw > Synchronize Diagram from the menu.
▪If you have a Sequence diagram open and in focus, selecting this command will change the partner Collaboration diagram so that it reflects the same information as the currently open Sequence diagram.
▪If you have a Collaboration diagram open and in focus, selecting this command changes the partner Sequence diagram so that it reflects the same information as the currently open Collaboration diagram.