I want to build a report which shows who is current assignee of the task and who was previous owner of the task.

@staceyw I understood that, but what I am trying to say is, the previous owner (as coined by @ambrishs) can be captured only when we make use of the Reassign Task built by us and the value holds valid only when OOTB 'Reassign Task' is disabled.

For instance, let's say we have reassigned a task using the functionality which is built by us by using the Reassign Task smart service. By doing so the previous task owner can be easily captured. Now let's say the user who is performing the task now, did some work and reassigned the task by using the OOTB 'Reassign Task' functionality. In this case if we go back to the Reassign Task functionality built by us, it still shows the previous owner as the person which is captured when we interacted with the functionality (but not the latest) and it definitely misses the person who has just now done some work and reassigned it.

Also may I please know if your idea is to trigger the exception also when the OOTB 'Reassign Task' is used?

@staceyw I understood that, but what I am trying to say is, the previous owner (as coined by @ambrishs) can be captured only when we make use of the Reassign Task built by us and the value holds valid only when OOTB 'Reassign Task' is disabled.

For instance, let's say we have reassigned a task using the functionality which is built by us by using the Reassign Task smart service. By doing so the previous task owner can be easily captured. Now let's say the user who is performing the task now, did some work and reassigned the task by using the OOTB 'Reassign Task' functionality. In this case if we go back to the Reassign Task functionality built by us, it still shows the previous owner as the person which is captured when we interacted with the functionality (but not the latest) and it definitely misses the person who has just now done some work and reassigned it.

Also may I please know if your idea is to trigger the exception also when the OOTB 'Reassign Task' is used?