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umlactivity-diagram

Should i use multiple outgoing control flow or decision node when a user can move to multiple actions after an action in Activity Diagram?

In an activity diagram I want to depict that after viewing the available events, a user can choose to book an event or cancel bookings of event he/she has already booked. So I think that i should be using decision node in this scenario. But I also think that since a user can only cancel booking after booking an event, "cancel booking" must be after "book event". Among the diagram given bellow which one is correct.

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Also I want do know if the first diagram is a valid diagram or not. There are several places in my diagram where based what the user is trying to do, he/she can move to different actions from a single action. Like in the diagram above a user can choose to create a new event, update an event or delete an event after viewing the list of all events.

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Is the diagram above valid or must I use decision node rather than creating multiple outgoing control flow? When is it okay to use multiple outgoing control flow rather than decision nodes?

Solution

  • A decision node or guard on the control flow would be better for me. This would alow you the fact that the user take a decision (to cancel, create or delete) before really doing it.