A NOTE ON THE EQUIVALENCE OF THE WILKERSON-IRWIN AND MODIFIED DUE-DATE RULES FOR THE MEAN TARDINESS SEQUENCING PROBLEM

We consider the problem of sequencing a set of simultaneously available jobs on a single-machine to minimize mean tardiness. Both the Wilkerson-Irwin (WI) and modified due-date (MDD) rules are effective heuristics for solving this problem. We show that the WI and MDD rules are in fact equivalent since both of them are based on the same local optimality condition for a pair of adjacent jobs. This provides some motivation to use the MDD and WI heuristics for the mean tardiness problem.