A Heuristic Algorithm for Job-Shop Scheduling to Minimize Total Weighted Tardiness

Abstract

This paper considers the job-shop scheduling problem to minimize total weighted tardiness since the due date of each job has been promised to its customer and it is most important to meet due dates. A heuristic algorithm based on the tree search procedure is developed for solving the problem. A certain job-shop scheduling problem to minimize the maximum tardiness subject to fixed sub-schedules is solved at each node of the search tree, and the successor nodes are generated where the sub-schedules of plural operations are fixed. Thus, a schedule is obtained at each node and a sub-optimum solution is determined among the obtained schedules. Computational results show that the proposed algorithm can find better solutions with little computation time and the number of generated nodes hardly increases even if the number of machines increases.