Read First: Event Diagram A termination event of an event diagram means "the event diagram has finished". The term "termination" is used, because an instance of an operation is terminated when the event diagram is finished. It is notated in OOIE with a bull-eye preceding it. The creation event does not contain any information about what will happen after the event diagram is finished, only that it has finished with certain values of its output variables. Trigger rules that finish an event diagram are notated in OOIE as arrows pointing to a bulleye node preceding the termination event. An event diagram can terminate itself whenever it likes, or never in the case of processes that do not end. Read First: Event Diagram