An iterated local search for unrelated parallel machines problem with unequal ready times

The problem considered in this paper is a set of independent jobs on unrelated parallel machines with sequence-dependent setup times and unequal ready times so as to minimize total weighted number of tardy jobs. An iterated local search (ILS) is developed to solve the problem. It employs a swap shaking procedure and a tabu search algorithm with hybrid neighborhoods to ensure high ILS effectiveness and efficiency. To evaluate the performance of the suggested heuristic, some heuristic rules, a conventional tabu search algorithm, and optimal solutions are examined for comparison purposes. The computational experimental results show that the proposed ILS is a promising method for solving this problem.