BPMN Modelling: No connection from one pool to a subprozess in another pool possible

Please also have a look on the attached .png. There you see how it does not work in the current ARIS Express release.

This is not a bug but the semantically correct BPMN implementation. You are not allowed to connect directly to objects in the subprocess according to the spec and therefore ARIS doesn't allow you to do this.

The correct way to do this is to connect to the subprocess object, because you should be able to create a valid BPMN diagram even when the subprocess is collapsed. When expanding a subprocess BPMN requires to include a complete, fully semantically correct BPMN diagram in that expanded subprocess (with start/end events and such *and yes, I know about implicit events, but I don't want to start this flamewar here*).

I addition to this ARIS will change your connection type to a "message" connection since you are crossing pools and then there are additional semantics/rules in using messages (message objects, message events, message tasks, message connections) in BPMN. Please have a look elsewhere in the BPMN group for a more detailed discussion on this -and a sane way to handle this complexity in real-life project situations.

I was going to comment, but Roland's already covered this point nicely.

The work around to move a connected box into a different pool usually pops up a window to ask whether you want to 'ignore constraints' and at this point your model is no longer semantically correct.

Regarding the specification this should be valid? Please correct me if i'm wrong.

BPMN 1.2 spec (p. 101)

"If there is an Expanded Sub-Process in one of the Pools, then the message flow can be connected to either the boundary of the Sub-Process or to objects within the Sub-Process."

BPMN 2.0 spec (p. 311, Figure 12.3)

Figure12_3.jpg

This is interesting and an inconsistency in the  2.0 spec IMHO (maybe from updating form the 1.2 doc, since that sentence was removed below the picture below). The example in 12.3 is from the Choreography chapter and not the Collaboration specification (chapter 9).

In that definition Figure 9.4 shows only a message flow to a collapsed sub-process, which is consistent with the characteristics of level consistency - e.g. throwing an end event to the border of the superior sub-process task while becoming an intermediate event.

-

When you look in the sub-process chapter (10.2.5) there is no hint that this is allowed, Furthermore, for some sub-process types it is explicitly forbidden (event sub-processes, ad-hoc sub-processes).

I also played around -very unscientificly I must admit- with our competition (BizAgi) and this process modeler also does not allow to draw message flows to tasks which are part of a sub-process.

I have a similar problem, but in the reverse direction.  I want to show messages from a task within a sub-process to another pool.  I see an example of this in BPMN 2.0 By Example from the OMG website, but ARIS won't allow it.  How can I show explicitly where a message comes from in the sub-process?

Hello,

It seems many people come across this issue using ARIS.

In this case, my interpretation of notation would be that, where it is not explicitly forbidden,  it means it is allowed.

as taking into account some inheritance, that BPMN v1.2 should be fully compliant with BPMN 2.0... I would not like to believe if in  v1.2 it was allowed to connect message flow with objects in sub-process, that now in v2.0 it would be restricted in all cases. Such modelling style  I guess is really widely used practice.

BR,

Ilze

I find the comments from @RolandWoldt somewhat confusing. A subproces can have a message interaction with events or tasks directly to a (black box) pool, which is reflected in the containing process also. This is in the spec, and expected if not mandatory functionality in a BPMN tool. Currently the unavailability of this in ARIS is for me unacceptable, and a real roadblock in modelling decomposed processes.