Rule of thumb from BAW Advanced projects:
| Use a BPD (BPMN in Process Designer) | Use BPEL (Integration Designer module) |
|---|
| People are involved: tasks, teams, coaches, portal, due dates, escalations | No people, or only through the old human task model you already have |
| The business owner must read and change the model | The model is technical (integration developers) |
| Long-running with waits on events / timers per business case | Short-running transactional microflows, or long-running system orchestration with compensation |
| Data is business objects edited in coaches, reported in the PDW | Data is XML / XSD from WSDLs and adapters |
| Snapshot-based deployment, instance migration, Process Admin | SCA module deployment, versioned modules, BPC Explorer |
Combination (the usual case in BAW Advanced): the BPD is the business layer; every system interaction that needs adapters, transactions or mediation is an Advanced Integration Service implemented in an IID module (Java, mediation flow or BPEL). Keep the AIS interfaces coarse ("Create policy", not "Insert row"), synchronous for microflows and asynchronous with the delayed response pattern for long-running ones (question 1025). Do not model human interaction in BPEL human tasks when you have BPDs, and do not orchestrate five back ends in a BPD with five sequential integration steps when one AIS could do it transactionally.
Direction of travel: BPEL / IID is not part of CP4BA containers; new designs use BPDs + service flows + App Connect Enterprise (or REST) for the integration layer, which yields the same split with different tooling.
References