Oracle BPEL 11g Best Practices

1. BPEL has to be primarily used for orchestrating the services. 
• Do not add complex business logic here. It should belong to the service layer.
2. Create scopes for each step of the flow in the process so as to make it modular.  This will help in creating local variables within that scope. Use Global variables when required(just like your java or C++ programming style). This will help in maintainability. Note : Adding too many scopes may affect the performance. In that case you may want top consider creating sequences.
3. Adopt naming standards and comply to it. This should be part of the governance strategy. This looks trivial but is important if you want someone else to understand the code and make changes.
4. It is good practice to have a Mediator in the Composite. Try to get most of the transformations done by the Mediator.
5. Have all the business rules implemented by the Oracle Business Rules
6. Handle all the exceptions
7. Adopt test driven development. Create test cases with a tool like SoapUI for each process and make this part of your governance strategy.
8. Instead of BPEL, you should consider implementing the process in BPM. This has the advantage of modeling it in BPMN so that it can be easily understood by the Business and also helps the model and implementation to be synchronized at all times. If you haven't considered it so far then it is time you take a look at 
9. The flow of the BPEL process should be very intuitive.
• The reason enterprises are investing heavily in this to be agile to change. So, to make this happen , make the steps in the flow linear as much as possible so that a new step can be added/reordered easily by just drag and drop. I have seen very complex nested creation of the following flow which after refactoring looks as below.