Dear Jayapathy,
To measure the performance accurately, you need to study the systems and processes of each department and then design the KPIs and KRAs for each department. Measures of performance for the individuals come later. Recently, I have given an exhaustive reply to a similar query. You may go through the following link:
https://www.citehr.com/526357-kpi-kra.html#post2228293
In this link, you will get further links. Go through all the links patiently and you will understand the gravity of the subject. For further doubts if any, you may call me on my mobile.
Thanks,
Dinesh Divekar