The Role of Standards in Business Process Management
Standards such as BPEL and BPMN play an important part in Business Process Management because they enable interoperability and ensure that certain ground rules are followed when architecturing the supporting software.
The fact that SAP NetWeaver Exchange Infrastructure supports BPEL is a sure sign that this is a standard to be taken seriously. BPMN plays a secondary role for SAP currently but will be come more important in the future.
BPX Viewpoint vs. Execution Engine Viewpoint
BPMN supports modeling business processes from the BPX's point of view rather than from an IT viewpoint, and yet the notation is precise enough to be machine readable. BPEL is a lower-level language whose constructs are geared to the architecture of a process execution engine. It is a common scenario for BPM suites to translate a model expressed in BPMN to a specification expressed in BPEL that can be directly executed by a process execution engine. BPMN thus is a bridge from the BPX to technology in the underlying BPM platform.
Translating BPMN to BPEL
BPMN-to-BPEL translations are typically semi-automated, meaning that they allow engineers who understand BPEL to configure how the translation is done, usually on a case-to-case basis. Because BPMN is at a higher level of absraction than BPEL, a BPMN model can usually be translated in more than one way.
For example, the BPEL that a BPM suite generates from a BPMN-based model may be different if execution needs to be highly distributed than it would be if execution needs to be controlled by a centralized orchestrater. This distributed vs. centralized execution issue is technical and thus does not surface in the BPMN model, which describes the business process without regard to such concerns.
Overview of BPMN
Although currently the most common business process modeling methodology in the SAP world is based on EPC (Event Process Chains), this article focuses on the technique for modeling business processes using BPMN.
Coming: BPMN 2.0
The Object Management Group (OMG), the standards body that manages the BPMN standard, recently kicked off an activity to create a major upgrade of BPMN. See the blog about BPMN 2.0. For those who wish to follow this activity, see this primer on the OMG standards development process.
The emerging BPEL4People standard, defines standards for how process execution engines interface with tasks that are performed by humans as, opposed to automated tasks. A wealth of material on BPEL4People is available on SDN.