Plant efficiency or plant overrun is the sum of separation, churning, composition overrun and package fill efficiencies. In summary the theoretical maximum efficiency values are:
Separation Efficiency 98.85
Churning Efficiency 99.60
Composition overrun (% fat) 23.30
Package overfill 0.20
These values can be used to predict the expected yield of butter per kg of milk or kg of milk fat received.