Single Machine Scheduling to Meet Due Times with Reduction in Processing Time

Abstract

In JIT environment, the basic assumption is that every job should be completed before or just on the due time when the customer requires it and leave the shop simultaneously on the due time. If a job is completed earlier than its due time, then the shop holds the job and incurs its holding cost for earliness. When the single machine scheduling problem to minimize the total weighted earliness under the constraint of due times is considered, a given problem will not be always feasible due to the conditions that jobs are not permitted to be tardy and starting times for all jobs are non-negative. Such a case causes trouble in practice, and suitable actions will be taken. This paper addresses the scheduling problem to meet due times with reduction in processing time for such infeasible problems. A heuristic scheduling algorithm is developed to minimize the sum of the reduction cost in processing time and the holding cost for earliness. The computational experiments are also shown for the proposed algorithm.