Batch production and preventive maintenance scheduling under equipment failure uncertainty

Abstract

This paper deals with production scheduling of multipurpose batch plants in the presence of equipment failure uncertainty. Uncertainty analysis is incorporated at the production scheduling stage to improve the probability of performing the resulting schedule. So, the need of complete rescheduling of the production plan is reduced and more effective reactive scheduling strategies can be applied each time a deviation from the expected plant status occurs. The probability of performing the predicted schedule will depend on equipment failure forecasts. The effects of equipment failure on the production schedule are minimized by computing the reliability indexes for each plant unit and for each scheduled task. Avoiding the use of equipment with low reliability indexes is balanced against production requirements (demand). Preventive maintenance tasks may be also introduced to compensate for possible delays produced by the use of equipment units with low reliability indexes. The incorporation of these methodologies into the overall planning framework is also shown and illustrated with case studies.