Implementing global factory schedules in the face of stochastic disruptions

The problem of implementing global factory schedules developed from an optimization-based heuristic in a manufacturing facility with executional uncertainties in the form of machine failures is considered. A simple procedure in which jobs are dispatched on the shop floor is proposed based on their start times in the global schedule. The performance of the proposed procedure relative to a number of well-known dispatching rules is evaluated using a simulation model of a scaled-down semiconductor wafer fabrication facility. Results indicate that the procedure combining the global schedule and dispatching outperforms the benchmark dispatching rules in terms of several performance measures as long as the level of variability in the system is compatible with the frequency of rescheduling.