UML: Two sequential token flows, random decision which starts first

Question

I'm looking for a way how to model two activity flows (in an activity-diagram), where it doesn't matter, which one starts first, but the second one has than to wait, until the first ends.

I know, there exist the start (split) and end (join) of concurrent activities. But they don't fit my needs.

Do you know any way how to randomly start the first flow but than process sequentially?

Answer 1

• Use Activity or Sequence diagram,
• Use an Initial Node or two for the random signal.
• You can also use Join for getting the signal into account.
• Use Decision node (not Fork!) for switching the flow.