Scheduling algorithms for parallel machines with sequence-dependent set-up and distinct ready times: minimizing total tardiness

Abstract

This paper considers the problem of determining the allocation and sequence of jobs on parallel machines for the objective of minimizing total tardiness. Each job may have a sequence-dependent set-up time that depends on the type of job just completed and on the job to be processed as well as distinct ready times at which the job is available for processing. These make the parallel machine scheduling problem more difficult than ordinary ones. Due to the complexity of the problem, two types of search heuristic, tabu search, and simulated annealing are suggested that incorporate new methods to generate the neighbourhood solutions. Three methods of obtaining the initial solutions are also suggested. Computational experiments are done on a number of randomly generated test problems, and the results show that some of the search heuristics suggested in this paper outperform the existing ones.