The triggering relationship describes a temporal or causal relationship between elements. The example below illustrates that triggering relationships are mostly used to model causal dependencies between (sub-)processes and/or events:
he triggering relationship is used to model the temporal or causal precedence of behavior elements in a process. The usual interpretation of a triggering relationship is that the source element should be completed before the target element can start, although weaker interpretations are also permitted.
Note that this does not necessarily represent that one behavior element actively starts another; a traffic light turning green also triggers the cars to go through the intersection.