Process Elements outside of a Pool

Continuing the discussion from Flow elements outside of pools/participants in Camunda Modeler? :

In this discussion it was stated that collaborations containing both a pool and process elements outside of all pools were not valid BPMN 2.0 and can therefore not be modeled in e.g. the Camunda modeler. As far as I understand it, the standard does allow these kinds of collaboration. 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 should not support this behaviour, or am I simply misreading the definition of the standard?
Cheers
Chris

PS: Thanks @nikku for redirecting me to a new topic and introducing me to the word “necrobump”

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If I understand the specification correctly, the Process on the figure 10.5 is still logically in a Pool (Participant). However, that pool’s boundary does not have to be drawn.

A Collaboration can contain two (2) or more Pools (i.e., Participants). However, a Process that represents the work performed from the point of view of the modeler or the modeler’s organization can be considered “internal” and is NOT REQUIRED to be surrounded by the boundary of the Pool, while the other Pools in the Diagram MUST have their boundary (see Figure 9.5).

Source: https://www.omg.org/spec/BPMN/2.0/PDF#page=141

Is there any reason that bpmn.io should not support this behaviour, or am I simply misreading the definition of the standard?

I think it’s just a missing feature. However, it might be difficult to implement correctly since the BpmnModeler does not know which Process represents the work performed from the point of view of the modeler or the modeler’s organization and I couldn’t find any XML property which could point us to such a Process.

We are happy to accept contributions so feel free to open a PR or an issue regarding this.

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To add to what @barmac said: We do not support everything the BPMN spec writes about, intentionally. We try to take the following things into account when building a new feature:

  • Is the use case wide spread enough so a large number of people benefit?
  • Is the use case free of magic, i.e. can it be edited and visualized without quirks?

To make it easier for our users we clearly distinguish between process and collaboration diagrams. What you’re showing there is an interesting mix. We do support that mix for rendering, however we do not allow users to create such diagrams.

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