#97 Confusing behaviour with "Call Activity"

[Robert STeiner]

https://youtu.be/Ozagzpk0I4E

I know that a global process can be an external BPMN file. But if Yaoqiang allows me to create a process, from a call activity, then this should either be forbidden or allowed.

Right now it is allowed, but I cannot insert a Pool into the process, because the software assumes a normal Sub-process

so.... I am confused..... is the problem on my side, or software side?

[Robert STeiner]

ok... I get it. All diagramms but the first, in each BPMN file, are sub-processes.

So I can only create Pool in the initial diagramm.

I guess those diagramms should be called "Sub-Process" instead of "Diagramm"

[史耀强(Blenta)]

All diagrams can contain pool, but if this diagram is called from call activity, it cannot have a pool.

[Robert STeiner]

https://youtu.be/4IZKyG04TzU

This is what I get. Or I am missunderstanding you.

[史耀强(Blenta)]

Sorry, I meant All diagrams can contain lane, not pool,

You are right, you can only create Pool in the initial diagramm.
All the diagram is saved as a bpmndi:BPMNDiagram element, so I call it Diagram.

[Robert STeiner]

I am still confused about the lanes. According to OMG BPMN 2.0

10.2.5 Sub-Processes
A Sub-Process is an Activity whose internal details have been modeled using Activities, Gateways, Events, and Sequence Flows.

and

9.2.2 Lanes
A Lane is a sub-partition within a Process (often within a Pool) and will extend the entire length of the Process level,either vertically (see Figure 10.123) or horizontally (see Figure 10.124). See page 305 for more information on Lanes.

and

10.2.6 Call Activity
A Call Activity identifies a point in the Process where a global Process or a Global Task is used. The Call Activity acts as a ‘wrapper’ for the invocation of a global Process or Global Task within the execution. The activation of a call Activity results in the transfer of control to the called global Process or Global Task.
The BPMN 2.0 Call Activity corresponds to the Reusable Sub-Process of BPMN 1.2. A BPMN 2.0 Sub-Process corresponds to the Embedded Sub-Process of BPMN 1.2 (see the previous section).

.
.
To my understanding, lanes cannot exist in a subprocess. My little BPMN 2.0 book, which was written by people who work together with the OMG also say explicitly:
(translated from german)
.
.

Since BPMN 2.0 a Subprocess is always embedded and can only be reused if defined as a "Global process" referenced by a "Call activity".
....
I an embedded subprocess, pools or lanes cannot exist,...

[Anonymous]

The above descriptions are all about Sub-Process.
But in Yaoqiang, each diagram tab represents a process, not sub-process.

[Robert STeiner]

hmmmmmmmmmmm.............No I am aware that BPMN is your daily food, But are you really sure? I am trying to point out, that only the first diagramm is a process. The others are not.
.
To my research there are only two types of processes. But I might be heavily mistaken.

In BPMN 2.0

Type	Usage
Process	Top Level Process
	Global Process (Also called Global/reuseable Sub-Process)
Sub-Process	Embedded Sub-Process
	Referenced Sub-Process

• A Process can contain pools AND/OR lanes
• A Sub-Process cannot contain pool OR lane
  .
  .
  I mean the first diagramm in Yaoquiang is a Process. It can be called from other BPMN files via "Call Activity". So it can act as a "global Process". But the other diagramms cannot be referenced as "Global Process". That makes them sub-processes, which belong to the parent process, which is the very first diagramm.
  .
  .
  .

[Robert STeiner]

https://camunda.org/bpmn/reference/#activities-call-activity
In this chapter they use the term "subprocess" for "embedded "subprocess" and "Global subprocess" as a reusable subprocess.

BUT... they also say, that a reusable subprocess can contain pools and lanes. So it is aquivalent to a normal process.

Right?

[史耀强(Blenta)]

All terms in this chapter are their private standards, not bpmn 2.0.

[Robert STeiner]

Sure? They are publisiung books in europe on BPMN 2.0. They are working with the OMG.

[史耀强(Blenta)]

There is no "reusable/embedded/global subprocess" in bpmn 2.0. Only one type "subprocess" is defined in bpmn 2.0.

[Robert STeiner]

There is a big misunderstanding here :) Yes BPMN 2.0 only uses processes and sub-process. I mentioned that in the table, column "Type" ealier. The column "Usage" referenced usage in the BPMN 2.0 Specs or terminology in other books. So the column "Usage" is a bit confusing sorry.
.
BUT
.
BPMN 2.0 says how you can actually use those two elements(process and sub-process). And then they use the words like "embedded" in their specification. Page 239 for example. Or "reused", you mentioned it yourself on page 146.
.
.
Anyways.. thats not my point. My point is, that I do not see how a process can ONLY contain lanes but no pools. But in Yaoqiang this is possible for all diagramms but the first.

[史耀强(Blenta)]

In BPMN 2.0 spec, there is only one type of process element saved in file. please see page 146 of spec.

A Process is a CallableElement, allowing it to be referenced and reused by other Processes via the Call Activity construct.

There is also one type of subprocess element saved in file. Reusable subprocess is in bpmn 1.2, not bpmn 2.0. in spec p176:

The reusable Sub-Process of BPMN 1.2 corresponds to the Call Activity that calls a pre-defined Process.

[Robert STeiner]

I agree. But a process can always contain pools and lanes. Your diagramms(except the first) can only contain lanes.

I do not see anywhere, how this complies to BPMN 2.0. :)

[Robert STeiner]

From the OMG BPMN 2.0 I cannot see how a process can NOT contain pools. And a sub-process cannot contain either pools nor lanes.

I referenced the chapters earlier.

[史耀强(Blenta)]

Please refer this issue list:
http://www.omg.org/issues/bpmn2-ftf.html

In Issue14803, discussed your question
http://www.omg.org/issues/bpmn2-ftf.html#Issue14803

[Robert STeiner]

Last sentence

Right now (v0.9.14), a sub-process can only contain flow elements and artifacts, not lanesets. I think we should allow lanesets in subprocess.

.
Answer is: Lanes are not allowed in a sub-process. This is what I read in the BPMN 2.0 asswell. As far as my brains allows it :)
.
But Yaoqiang allows lanes in a sub-processes. NOW...earlier you wrote:

All diagrams can contain lane,

.
But the problem is, that only the initial diagramm can contain pools and lanes. Therefore it is a process. The other diagramms cannot contain pools. Therefore they must be sub-processes. But in a subprocess must not be a lane.
.
.
Therefore Yaoqiang is not compliant with BPMN 2.0 is it not ?

[史耀强(Blenta)]

I think you should check bpmn20.xsd.

I think we should allow lanesets in subprocess.

Finally, lanes are allowed in subprocess.

[史耀强(Blenta)]

Here is the schema.

[Robert STeiner]

ok... that's intertesting. ...

[史耀强(Blenta)]

Afte you understand this, we can talk about Pool.

If you check the bpmn schema, you won't find pool. Why? in bpmn spec:

A Pool is the graphical representation of a Participant in a Collaboration.

It just a graphical representation. It is only allowed in Collaboration diagram.

[Robert STeiner]

Ok.. we were talking about lanes in a subprocess. They are allowed. OK.

Earlier you wrote, that each diagramm tab in Yaoqiang represents a process. If that's so why aren't pools allowed in all diagramms?

[史耀强(Blenta)]

Because there is only one Collaboration Diagram, all other diagrams are Process diagram which contains only process element.

[史耀强(Blenta)]

The first diagram represents a process if it contains only process elements.

[Robert STeiner]

oki doki..... jesus :)