using a p control chart for joint optimization of maintenance, quality, and buffer stock policies in single machine production systems

The aim of this study is to deal with the joint optimization problem of maintenance scheduling, quality control, and buffer stock planning in a single machine production system based on a p control chart. it is assumed that there is a fixed production rate and stochastic machine breakdowns, which directly affect the quality of the product. a buffer is used to reduce production disruptions caused by machine stops and to ensure demand is met during preventive and corrective maintenance. all features of three sub-optimization problems, including maintenance, quality control, and buffer stock policies, are formulated, and the proposed integrated approach is mathematically modeled. in addition, an iterative numerical optimization procedure is developed to provide the optimal values for the decision variables. the proposed method provides the optimal values of preventive maintenance scheduling, buffer stock size, sample size, sampling interval and control chart limits simultaneously, so that the total cost per unit time is minimized. it is found that performing preventive maintenance reduces the overall costs incurred. moreover, some sensitivity analyses are carried out to identify the key effective parameters. significant economic benefits can be seen in the proposed joint optimization procedure.