When Rounding of Fractions is performed in FOQ (Fixed Order Quantity) or PPB (Part Period Balancing), the difference between net requirements and the rounded quantity of scheduled order is called Surplus. The surplus is allocated to the net requirements for subsequent period.
For example, as shown in the figure, the quantity of scheduled order for Period 1 is originally 55, but it turned to be 60 by rounding it, and as the result surplus (5) occurs. If the calculation to allocate the surplus is not performed, the net quantity (35) of scheduled order for Period 4 is rounded to be 40. But by performing the calculation to allocate the surplus, the surplus (5) for Period 3 is allocated to the net requirements (35) for Period 4, and the quantity of scheduled order is 30.


Related term: Rounding of Fractions