FUML15 — fUML should include interruptible activity regions

Interruptible activity regions are currently excluded from the fUML subset "because they are considered to be more appropriate for 'higher level' process modeling and outside the scope of fUML" (see subclause 7.10.1 of the fUML 1.4 specification). However, in the specification of the detail behavior of an asynchronously running activity, it is often useful to be able to break out of some ongoing behavior when some event is accepted. Using an interruptible region is the most convenient way to do this, and this is not really "higher level" process modeling.

Indeed, using interruptible regions in this way is common in SysML activity models. And current ongoing work on specifying the precise semantics of SysML 1.7 will need to include the semantics of interruptible regions. However, since this semantics is not really specific to SysML, it would be better if it was specified within fUML.

Out of scope

The RTF has decided that this to large a change to the scope of fuml to be handled in the RTF process. Adding this capability to fUML would be better handled by an RFC or RFP process.