Migration Points
Process migration can only occur at specific points in the process template. These points are called migration points. Migration points are automatically identified by TIBCO Business Studio at design-time.
Tasks, events and gateways are defined as migration points but not all tasks, events and gateways are eligible to be migration points, see Determining if Migration is Valid.
You can only migrate a process instance at the exact same migration point in the earlier or later process template. For example, if you select the Display Message task in the source process template, then the Display Message task is automatically selected in the destination process template. You can specify one, some or all of the migration points in a process template, depending on your requirements.
The point at which the active process instances migrate depends on the point they have reached in the process. Migration occurs when the process instance is about to execute a task that has been scheduled for migration. If the task has already been offered to a user or executed, in other words, the work item has already arrived in the work list, it is too late to be migrated and migration will take place at the next migration point specified or, if no other migration points have been specified, carry on with its existing process template version, see Process Migration Example.