Optimal production model for imperfect process with imperfect maintenance, minimal repair and rework

摘要

This study considers the integrated problem of production, preventive maintenance (PM), inspection, and inventory for an imperfect process with minimal repair, PM error and rework. We develop a model for optimising the number of inspections, the inspection interval and the economic production quantity. The model assumes that the production process is in either the in-control state or the out-of-control state. If the production process is in the in-control state, then PM is performed. If the production process is in the out-of-control state, two process shifts are possible. The first type is a relatively mild production process shift in which a minimal repair can restore the process to the in-control state. The second type is a more serious shift that completely stops the production cycle. Numerical analyses are used to investigate the effectiveness of imperfect PM and to explore how profit is affected by minimal repair, PM error and rework.