A new dispatching mechanism for parallel-machine scheduling with different efficiencies and sequence-dependent setup times

Abstract

The Apparent Tardiness Cost (ATC) dispatching rule was initially developed to minimize tardiness in single-machine scheduling problems. ATC extensions have been frequently applied in other production settings, relying heavily on blocking idle machine capacity with a single-machine outlook; this approach may not result in the best outcomes, considering that machines have different efficiencies. This study develops a new dispatching rule for parallel-machine scheduling, considering different machine efficiencies, ready times, and sequence-dependent setup times to minimize the total weighted tardiness. The proposed method reduces the time interference factor of the denominator item in the dispatching rule and uses more effective methods for selecting the best processing machine for the jobs. The grid approach is used to evaluate the method against the state-of-the-art. The experimental results confirm that the developed method is superior regardless of the type of parallel machines, the problem scale, and other operational parameters. It is also shown that other ATC dispatching rules can be improved by applying the proposed approach. The proposed method could be incorporated into soft computing techniques for more effective and efficient scheduling.