Flow elements outside of pools/participants in Camunda Modeler?

Users
#1

I would like to reconstruct the image at https://knowhow.visual-paradigm.com/know-how_files/2009/12/09_eventbased_gateway_thumb1.png, from the page https://knowhow.visual-paradigm.com/business-process-modeling/bpmn-gateways/ - included below:

The problem is, this image shows a “Customer” pool/participant on top, and then Start, StopEvents, etc outside of the pool/participant. But if I try to do the same in Camunda,

  • if events etc were placed first, then placing a pool/participant automatically wraps the events;
  • if I put the pool/participant first, and then try to drag the events deliberately outside of it, I am warned with a message: “flow elements must be children of pools/participants”, and whatever elements I’ve placed are removed:

So, basically, I cannot find a way to reconstruct the above image.

Is there a way to do this in Camunda; and if not, is this a bug in Camunda - or does this have to do with the BPMN 2.0 spec (maybe it is stricter, and the original image I posted was done according to earlier BPMN specs)?

Process Elements outside of a Pool
#2

The diagram on your picture is not correct BPMN 2.0.

In BPMN 2.0 you have to chose between the following options:

  • modeling a process --> means that there are no pools at all
  • modeling a collaboration --> means any BPMN element has to be inside of a pool

You cannot mix the two if you want to be compliant with the BPMN 2.0 standard specification.

Our modeling tool is fully compliant with the standard so we do not allow to model anything that is not allowed by the standard.

There is also reasoning behind it. When modeling message flows in the BPMN there always has to be a sender and a recipient of a message and these refer to the participants. So in your example it is not clear who is actually sending/reciving the messages.

Cheers
Robert

#3

Hi @robertgimbel, many thanks for the answer:

I do not have a full knowledge of the spec, so I couldn’t have guessed that image was not correct - thanks for clarifying that…

Cheers!

#4

One might make a mistake though. Somebody plays around with it and saves it.

#5

You’d like to remove the Pool but keep the contents? Right now there is no easy way to do this except for

  • Copy contents
  • Remove everything
  • Paste contents

It is not the main direction you’d usually evolve a diagram in, too :wink:.

#6

Hi everyone,
I am aware that this discussion happened some time ago, but the issue came up in a discussion this week and perhaps some of you have some input on this:
As far as I understand it, the standard does allow these kind of collaboration, wherein you have pools and a process outside of it. For example, such a collaboration is depicted in Figure 10.5 of the BPMN 2.0 standard, and on page 113 thereof it is explicitly stated that a collaboration may contain pools as well as one process not wrapped by a pool. Is there any reason that bpmn.io/bpmn-js should not support this behaviour, or am I simply misreading the definition of the standard?
Cheers
Chris

#7

Hi @ChrisSchoe, welcome to our forum!

Please do not necrobump old topics. Instead link to this thread from new topic.

#8