A survey of priority rules for FMS scheduling and their performance for the benchmark problem

The results of a comprehensive evaluation of priority rules for a multimachine cell are discussed. The performance of the rules is compared for a wide range of operating conditions, in particular, different average queue lengths and time pressure levels. It turns out that three rules are superior to the others: CR+SPT (critical ratio plus shortest processing time) with respect to the mean tardiness (at the expense of a small number of jobs suffering very large delays) and SL/OPN (slack per remaining operation) and ODD (earliest operation due date) with respect to the root-mean-square value of tardiness and the maximal tardiness. The authors also present a priority rule based on an analysis of the situation in the queue after the next operation is scheduled rather than before any operation is scheduled. This rule combines the strengths of the two extreme solutions