Will BPMN 2.0 make BPEL irrelevant?

As technology is speeding up, the lifecycle of standards is shrinking.  Business Process Execution Language or BPEL is one good example.  BPEL has its origins in competing standards sponsored by IBM and Microsoft, WSFL and Xlang.   The two languages were merged in April 2003 and over just a period of three years BPEL has become the most popular business process execution language.  BPEL is used extensively in SOA environments because BPEL was designed with Web Services in mind and this matches well with the tight coupling of SOA and Web Services.  While generally complementary, BPEL is now being challenged by a different technology from Object Management Group OMG called Business Process Modeling Notation (BPMN).

BPEL is a language that describes the flow and coordination of interactions between published business component interfaces.  Typically those interfaces are implemented as Web Services.  Note that the “EL” at the end of the BPEL acronym refers it as an “execution language” as distinguished from a “notational language”.  What this means is that while BPEL is a “workflow tool”, it doesn’t really provide any kind of graphical layout modeling capabilities.  As such, it is a fairly low-level language based on XML that provides a standard way for describing the business process flow.  BPEL language is used to create instructions that are fed into a BPEL server that in turn coordinates the activities of the business process.

Working with raw BPEL requires a solid understanding of XML and software logic.  BPEL requires that business requirements be first captured and translated before being rendered into the BPEL logic.  The gap between specification and BPEL implementation can isolate business analysts from IT groups.  The solution is to bridge the gap between these two groups by creating higher level model tools that allow the graphic creation of a the business process flow and output BPEL language.  These kind of tools exist, but there is no standard for these higher level tools.  This is where BPMN comes in the picture by attempting to standardize business process modeling.

BPMN is a notational language that can graphically describe business processes.  With BPMN, the process flow is depicted with a network of lines showing interactions between components represented as shapes like circles, rectangles and diamonds.  It provides standardization in creating workflow diagrams.  Graphic workflows represent the classic image of what “Workflow” is all about.

Because BPMN describes the business process from a higher-level perspective, it can include information about human steps and interactions in the process that fall outside of the control of software.

So, BPMN and BPEL seem to be complementary technologies and perhaps that is how the two will develop:  BPMN tools would be used during business analysis and modeling, and from the BPMN model, a BPEL representation would be generated and output and used for execution.

Stepping back a little more though we see that BPMN and BPEL both express the flow of the business process, but the BPMN process model representation is more useful to the business analyst.  BPMN is addressing the model level and BPEL addresses execution.  Because of that, the importance of having a standard for the execution language is less relevant.  BPMN models can be exchanged and exactly how the models are translated and executed is less relevant.

What happens next isn’t clear.  It should be noted that BPEL may further evolve and this is likely to happen because of its current high level of acceptance.  Another factor in how this all plays out is whether BPMN will be actually accepted.  OMG intiatives have not always been met with unanimous acceptance.  Right now though the reaction to BPMN 2.0 seems positive, so it is likely that BPMN-based tools should begin appearing.

In any event, the good thing is that after many years of very many proprietary tools for both business process modeling and execution that the industry will be moving towards standardization.  At Formtek, we frequently see business solutions comprised of both ECM and BPM components, and as a partner with Oracle, we are very familiar with Oracle’s BPEL Process Manager.  Both Oracle and IBM have been strong proponents of BPEL technology.  It will be interesting to see the evolution of these technologies and the response of leading vendors like Oracle in this area over the next 18-24 months.