As I mention in another question, there is a simulation framework being created right now that will allow you to simulate, debug and reproduce business scenarios including rules, processes and events. This integrated simulation framework allows you to reproduce complex scenarios and not just business processes. How you integrate that with your environment is up to the specific implementation domain.
From the JBPM5 download section you will find a file named jbpm-5.2.0 Final-examples.zip.
This contains a collection of business process examples - but more importantly a suite a testcases that use a specialised JUnit runner to handle the establishment of the container to execute the process definitions. You can work though these examples to see how business processes can be tested inside a continuous integration environment, and how test metrics can be generated.