READY-TIME SCHEDULING WITH STOCHASTIC SERVICE TIMES

A frequently encountered scheduling problem is to determine simultaneo usly a material and job ready time and production sequence based on cu stomer-specified due dates. Each job has a stochastic production time and a deterministic due date. The ready time is constrained in that th e probability that each job will be complete by its due date must meet some minimum level of confidence. The objective in such an instance i s to postpone the ready time as late as possible without violating the se constraints. The steps and effort necessary to determine the maximu m ready time and optimal production sequence, and cases in which this effort may be significantly reduced are presented. The resulting model is applied directly to single-facility and flow-shop production envir onments. Methods are shown for scheduling in a dynamic environment.