I’m struggling to see what to use the OAS for. So far I have this:
OAS: Displays activities and the interactions between activities and includes timing information.
OES: All of the above but also includes actors.
If the OES is just the same information as the OAS plus actor information, what is the use of the OAS?
Thanks for your help,
OAS can be useful to focus on sequencing of activities if the allocation of activities to operational actors is not yet defined or may change.
It allows to have a formalized sequence which will not change even if allocation is modified.
But as you said, OES covers the information available in OAS and provide additional information.
It is never mandatory to use all kind of diagrams. Only use the kind of diagrams which best fit for your need!