EMQ Model with Maintenance Actions and Warranty Policy for Imperfect Production System

This paper studies the optimal production run length for the economic manufacturing quantity model with maintenance, scrap and rework actions under the imperfect production system where the process state is classified as either in-control or out-of-control. Suppose that a production process starts to produce in an in-control state, however, after a period of time, the process may evolve from this in-control state to an out-of-control state in which more nonconforming items are produced than in the case of an in-control state. Thus we are taking restoration cost, disposal cost and reworked cost for nonconforming items into account in this paper. We show that there exists a unique optimal production run length such that the expected total cost is minimized. In addition, bounds for the optimal production run length are provided to develop the solution procedure. Finally, a numerical example is given to illustrate the results.