Abstract: A method and system for computing a supply chain planning process efficiency E in relation to manufacturing activities of an organization. Input data, including supply and demand input data, is received beginning at time T0. An iteration index R is set equal to 0. Then the method and system implements: incrementing R by 1; adjusting the input data (i.e., changing, deleting, or updating the input data); executing a central planning engine (CPE), using the input data; analyzing results of executing the CPE; and iterating, or computing and stopping. The iterating repeats the incrementing, adjusting, executing, and analyzing. The computing computes E. E may be a function of Q, C, and RP/T. Q is a manual edit ratio in conjunction with adjusting the input data, C=S/D, S is supply, D is demand, T=TE−T0, and P is a real number.