Message from sub-process

If I have a Send task within a sub-process, which needs to send a message to something in a different pool, how do I show this (a) in the sub-process diagram, and (b) in the main process? Presumably the message flow needs to go to some kind of boundary object on the sub-process diagram, and the sub-process symbol on the main diagram needs to show a similar boundary object from which the message emerges and from which it can then be connected to something in another pool. But what are these objects? I can’t see anything suitable in the palette…

Thanks - Rowan

I’ve found a solution to this:

On the main diagram, just show the message flow from/to the collapsed sub-process inside the main pool to/from the “black box” pool.

On the sub-process diagram, also show the black box pool, which should be named identically to the one on the main diagram, and show the message flow going from/to the message sending/receiving task or activity or event within the sub-process to/from the pool. Don’t show the pool which the sub-process is in.

I’ve read somewhere that pools should not be shown on sub-process diagrams because they are implicitly inside the pool on the main diagram (which always has a pool, whether explicitly shown, or implied). If this is the case, then any pool shown on a sub-process diagram would be inside the main diagram pool, i.e. it would be nested, which is not allowed. That’s why I had not tried this before.

However BPVA allows you to do what I’ve described above, and it seems a reasonably intuitive way of showing what’s happening. Also, I understand that it’s valid BPMN2 and that it doesn’t break the rules for BPMN execution.

I’d welcome comments from any BPMN experts on this!

Thanks - Rowan

I agree this is the most appropriate way of modeling the case you said :slight_smile: