No abstract

This paper proposes exact algorithms to generate optimal timing schedules for a given sequence of operations in job shops to minimize the total weighted earliness and tardiness. The algorithms are proposed for two job shop scheduling scenarios, one involving due dates only for the last operation of each job and the other involving due dates for all operations on all the jobs. Computational experiments on benchmark problem instances reveal that, in the case of the scheduling scenario involving due dates only for the last operation of each job, the proposed exact algorithms generate schedules faster than those generated using a popular optimization solver. In the case of the scheduling scenario involving due dates for all operations on all the jobs, the exact algorithms are competitive with the optimization solver in terms of computation time for small and medium size problems.