The 2 submitting teams’ proposals for version 2 of the BPM notation standard, BPMN, were presented at OMG this week. As CEP pundits know, BPM is used for simple event processing with manual workflow components, and BPMN provides a means of representing the simple event orchestrations [*1] ideal for representing business processes.
One of the interesting aspects of the BPMN 2 proposals [*2] is the inclusion of choreography modeling. This of course makes sense: many business processes are choreographed (i.e. require an ordered or partially-ordered sequence of messages or events). Having said that, describing complex choreographies in a flow diagram [*3] may not always make sense. When you think about it, a choreography is simply about having particular responses to patterns of events. And of course, CEP technology is one good way to model such event patterns…
A related issue in BPM(N) is exception handling (which could be viewed as a kind of process-oriented BAM). Modeling process exceptions can, in certain cases, cause complications in (or, some would say, pollution of) process flows. Especially in complex flows, such as exceptions to the choreographed message flows mentioned above. One way of mitigating this is to apply / define declarative exception rules alongside the process flow. And of course where your business process is dealing with real-time continuous events, a CEP engine may be the best bet to detect such exception patterns and/or drive the underlying workflow.
Notes:
[1] Some CEP tools use a process diagram notation to handle processing of event streams / sources. Usually these have a subtly different semantics over standard BPMN (for example, apply a pattern detection process over this timespan over this data feed). BPM is normally concerned with the event-as-an-invocation model of non-continuous processes. We’ll return to the topic of continuous event process flows / BPMN for CEP in a later blog…
[2] Note that as TIBCO is a major BPM vendor, our BPM team is closely tracking the “Extend BPMN” and “Merge BPDM and BPMN” proposals (earlier commentary here). Expect TIBCO iProcess and BusinessStudio to continue to provide full support for BPMN as it evolves.
[3] The same also holds true for representing complex / re-used business rules in BPMN process diagrams. Often these simply complicate the BPMN diagram and should be externalized into rulesets that can be shared across different parts of the process flow / processes.
