In an earlier blog post I explained that the Object Management Group (OMG), the standards organization that owns the BPMN specification, had issued an RFP inviting member companies to submit proposed BPMN 2.0 specifications. In a subsequent post, I outlined the process that the OMG follows for evaluating and ratifying submissions that it receives in response to RFPs.
Since then, two teams of companies have submitted proposed specifications. Their contributions are called "initial submissions," so they are not yet complete, but they are substantive enough to make evident the different approaches that they take.
One submission is called BPMN for Services (BPMN-S). The other one does not have an official name, so I'll refer to it as the BEA-IBM-Oracle-SAP submission, since those companies constitute the initial submission team.
The submissions have four aspects: Metamodel, notation, interchange format, and execution semantics. The RFP requires that these aspects cover choreography and orchestration processes.
The biggest difference between the two submissions is in how they define the BPMN 2.0 metamodel. The BPMN-S submission positions the OMG's Business Process Definition Metamodel (BPDM) as the metamodel for BPMN 2.0. The BEA-IBM-Oracle-SAP submission defines a dedicated BPMN 2.0 metamodel, and proposes a mapping between the dedicated metamodel and BPDM.
Metamodel
In order to explain the differences in approach to defining the BPMN 2.0 metamodel, I should provide some background on BPDM.
The OMG issued the BPDM RFP in 2003. The RFP opens with a statement of its objective:
"This Request For Proposals solicits submissions that specify a business process definition metamodel, which is platform independent with respect to specific business process definition languages. This metamodel will define an abstract language for specification of executable business processes that execute within an enterprise..."
After initial submissions came in to the OMG, BPDM languished with little to no activity for quite some time. In 2006, activity picked up again, led by a new set of players, who are the same parties that form the core of the BPMN-S submission team. BPDM is now going through the final stages of completion. The BPDM specification includes a mapping to BPMN notation.
The BPMN-S submission uses BPDM as the metamodel, and uses BPDM's mapping to BPMN notation.
The BEA-IBM-Oracle-SAP submission takes the position that BPDM is not a metamodel of BPMN; rather, it says, BPDM is a metamodel of a new, abstract language for process that, as envisioned by the BPDM RFP, was intended to be mapped to multiple concrete languages. BEA-IBM-Oracle-SAP approach is that BPMN, as one of those concrete languages, requires its own metamodel, whose constructs are clearly recognizable as BPMN elements. The submission says, furthermore, that if BPDM is to play a role in the BPMN picture, it should be via a mapping between its abstract language metamodel and a concrete BPMN language metamodel.
Merger Talks
The two submission teams are actively engaged in discussions about a possible merger. While these talks are going on, the parties are reluctant to disclose the content of these negotiations. During the public March 2007 OMG meeting in Washington, DC the two teams presented their submissions to the OMG's Business Modeling and Integration Task Force, which has jurisdiction over BPMN. For the next two and a half days, the two teams met privately to explore the possibility of working together for one unified submission, and discussions have continued since then.
Stay Tuned
The process of defining BPMN 2.0 is moving quickly, and I will provide updates as new developments occur. While I've highlighted a key difference between the two submissions, there are some other differences that I'll try to cover in future posts of this blog.
