In Latest source jbpm uses the name instead of the id for processes...
In my opinion this is the wrong behaviour as the name of a process will be converted to a id.
So if you want to start a process via: executionService.startProcessInstanceByKey("process4711") it will throw a exception.

Example Process for this:
<process id="process4711" name="Could be a very long description and is not used to IDENTIFY">