For you who read this blog on occasion, please help. I am looking for any valid BPMN diagrams that can not be represented as standard XPDL. Many people understand that XPDL is a superset of BPMN, meaning that everything from BPMN can be represented as XPDL, while the converse is not necessarily true. There are, however, a few vocal opponents who claim that XPDL can not be used to store BPMN.
OK. Both BPMN and XPDL are complex subjects. I know that when creating the XPDL 2.1 specification, a detailed examination of the BPMN spec was made, and every attribute of every element was accounted for in the XPDL file format. It is possible that one was missed, and it is possible that there are combinations of things that somehow can not be represented. While I doubt this is the case, I have an open mind for discussing the possibility.
What I need from you: Can anyone identify a BPMN diagram that can not be expressed as standard XPDL. I really want to know if any such diagram exists.
No extended attributes necessary: XPDL has an extended attribute mechanism, so of course XPDL could be used to represent anything, but to keep things fair, I am only talking about standard XPDL elements that are fully defined in the XPDL spec. There must be a standard way to represent the BPMN diagram, and if you can identify a BPMN diagram that requires extended attributes, then that counts as well.
Anything in the BPMN Spec: The current BPMN revision is 1.2, and so any element defined by that spec can be included as long as it is used in the way that that specification defines as proper use. Naturally, vendor specific extensions to BPMN may require extended attributes in XPDL, but this challenge should avoid proprietary extensions of either standard.
That is it. If you can draw any valid BPMN diagram that can not be represented as standard XPDL, I will write a follow on post discussing the gap. Write a comment, or let me know how to contact you to get the graphical image. Thanks in advance.