BPMN2 — Generalize message flow

The specification contains this constraint: Note that Message Flow cannot connect to objects that are within the same Pool.

There is no reason to have this constraint and it artificially constrains the model. Many process modeling paradigms (including UML) provide for flows between activities within a process. It is common to refactor processes in which case the interactions don't change - but they may move to another pool. From a business perspective we may well have a message between activities, even if we have not delineated all the participants. The constraint should be removed. This could be acheaved by a more general treatment of interactions.

Comments:
From: conrad.bock created: Wed, 15 Oct 2008 09:48:03 -0500 (CDT)
Related to <a href="http://www.osoa.org/jira/browse/BPMN-229">http://www.osoa.org/jira/browse/BPMN-229</a> (Mariano is working on it).

From: bruce created: Fri, 5 Dec 2008 18:52:24 -0600 (CST)
This would fundamentally change one of BPMN's core concepts, message, which currently is any type of signal exchanged between processes (pools).

From: mariano.benitez created: Wed, 10 Jun 2009 13:36:58 -0500 (CDT)
One way or another, we need a resolution for this problem with pools and processes.

I personally think we should allow message flows between activities of the same process, or even between processes, but without a collaboration diagram. Collaboration diagrams seems like an overkill for me in the case of simple inter-process synchronization (private processes that add up to the big business process).

This proposal would change basic design principles in BPMN. Hence, we do not want to fix this.
Disposition: Closed, No Change