UML22 — Suspension Region

“Supspension region” is a concept from MSC-2000 that occurred in earlier drafts of UML 2.0. It was removed since the metamodel had not been properly updated. A suspension region is an area of a lifeline where no events should occur since the lifeline is waiting for reply from an operation call.

This has been flagged as a potential FTF issue before.

Discussion:
This is a concept that highlights a syntactic requirement. Often users think that suspension is always the case between call and reply, but since lifelines may be decomposed into independent sub-parts, this is not necessarily the case. That is why it is useful to clarify a synchronization situation. Still it is a new concept, and cannot be considered critical for the use of Interactions. Let us bring this up again at a larger revision.
Disposition: ClosedOutOfScope