are the OR control nodes in an activity diagram (sequencing) an exclusive OR or an inclusive OR? I saw the below picture in one of the presentations (link: Unleash the power of functional chains with Capella 1.3.1 | PPT). I want to know what happens if the guard condition is true for both cases.
Will F2 and F3 be ever executed at the same time? Are OR nodes equivalent to the Decision-Merge node combination in UML?
Thanks and Regards,
I don’t have all the answers, but if yo want to have more precise semantics on timing, Scenarios are a better solutions.
First thing to note is that Arcadia does not support Activity Diagrams. The view you have replicated above is a Functional Chain Description diagram. These can be used to show an order of sequence/execution by the use of sequence links and control nodes (OR, AND or IT).
I have interpreted the sequence links to be similar to control flows in SysML which means they are simply used to specify an order of execution and not representative of actual information flow. Thus, F1 generates a logical token that could only ever have one value at any one time; meaning either F2 or F3 gets executed (exclusively).
Except for some very trivial situations I would avoid this kind of notation in favour of ES or FS views (as @StephaneLacrampe suggested) as they tend to be too ambiguous in their interpretation.