Why manday work and measurement rate analysis by manpower engagement need?

For measurement rate analysis we need production rate and one man day labour charge. For production rate we need the measured quantity done by one worker in one manday (8 hours are equal to one manday and take 8 hours labour charge, if you take 12 hours man day then 12 hours labour charge is required). This calculation should be done in average condition, then we can do further calculation.

What is the manday work and measurement rate analysis by manpower engagement formula?

a= measurement quantity in unit
b= average worker rate for manday
b= (skilled rate + unskilled rate)/2
c= contractor profit in %
d= total worker engaged for one manday
e= total time worker engaged to complete quantity in mandays
manday work or production rate in unit/manday , w
measurement rate or labour charges for measurement work, z
manday work or production rate= measurement quantity/ total manpower engaged to execute total measurement quantity in mandays
measurement rate = one labour manday charge with contractor profit/ production rate
w = a/(d*e) unit/manday
z = (b+b*c*0.01)/w currency/unit