Scheduling jobs on parallel machines with sequence-dependent setup times, precedence constraints, and ready times using variable neighborhood search

In this paper, we discuss a scheduling problem for jobs on identical parallel machines. Ready times of the jobs, precedence constraints, and sequence-dependent setup times are considered. We are interested in minimizing the performance measure total weighted tardiness. Scheduling problems of this type are quite important in semiconductor manufacturing. We suggest a variable neighborhood search (VNS) scheme for this problem. Based on computational experiments with stochastically generated test instances we are able to show that the VNS approach clearly outperforms heuristics based on the apparent tardiness cost with setups and ready times (ATCSR) dispatching rule in many situations.