Hi,
I think it is not possible to do this automatically.
Lets assume you have a simple workflow:
Start–>Task1–>Task2–>end
and you would change this to
Start–>Task1–>Tast3–>Tast2–>end.
How should the system know how to migrate? Should they all go back to the first, second or third? What if data was already commited via a webservice? The migration will always be a brain breaker.
However, it would be nice if we could say: move all processes being at a specific step to a new version of the process at a new specified step. (I suppose this is not possible).
Just an idea…