Difference between Process, SubProcess, Tasks

[sbhatti]

Though, I have read jBPM manual, but it is unclear the difference between processes, subsprocesses and tasks and when will I use one as opposed to other. Can someone elaborate it? Second question is about saving workflow state. I saw that save method is used to save the state when jBPM is used with the database. Can jBPM saves state automatically between each step. Also, I am assuming that if jBPM is running without database then no state will be saved between steps. Is that correct?

Thanks in advance.

[jbpmndc]

A process definition defines a process. In the process definition are task nodes that break that process into discrete units. A task node can be broken down into individual tasks.

[sbhatti]

Well, I sort of get very high level view of process and tasks, but my question is really how they are treated differently by jBPM and when will you use one against another. For example, does the state is saved between processes, but not between tasks. I am planning to use jBPM in sort of BPEL like way, where I can define services either in chains of commands or workflow like (with forks), so I need to see whether it make sense to define call to each service as a process, subprocess or task.

[biggef]

I have a more practical question: how to include a sub process ? Does it have to be defined in the same processdefinition.xml file as the main process ? With the same tag or is there a special tag for a sub process ?

Thanks in advance for your answers.

[kukeltje]

look at the testcases, there you will see they are defined externally

[kukeltje]

and of course the documentation