Combining preventive maintenance and statistical process control: a preliminary investigation

The economic design of control charts and the optimization of preventive maintenance policies are two research areas that have recently received a great deal of attention in the quality and reliability literature. Both of these research areas are focused on reducing the costs associated with operating manufacturing processes. In addition, it is widely recognized that the maintenance of manufacturing equipment and the quality of manufactured product are related. However, these two research areas are rarely integrated. In this paper, a combined control chart-preventive maintenance strategy is defined for a process which shifts to an out-of-control condition due to a manufacturing equipment failure. An Xmacr chart is used in conjunction with an age-replacement preventive maintenance policy to achieve a reduction in operating costs that is superior to the reduction achieved by using only the control chart or the preventive maintenance policy. This superior cost performance is demonstrated using a simulation-optimization approach.