Look at the following data:

Service departments Operation departments

Admin Bacs Accounting others

Department cost before allocation Rs $180000$ Rs $90000$ Rs $190000$ Rs $900000$

No$.$ of employees $15102080$

No$.$ of PCs $22018102$

Other information is as follows: Bacs: Business administration computer services

What are the service departments? Show the allocation bases with respect to the service departments. Then, rank the service departments for step down method of redistribution of OH$.$ Give proper reasons for your ranking of service departments.