Hi Debyani,
I would say it's not unethical to compare different departments, but I feel one department naturally depends on another department. So, either the Primary department, which is going to start the implementation, is given forced ranking, or the department which reaps the benefits of the implementation is given the forced ranking. In between, the transfer of work among several departments receives less recognition when compared to the scenarios mentioned above.
I guess I am not confused or confusing others; this is what I have observed in many industries to a large extent.
Regards,
srilatha