JOINT DETERMINATION OF ECONOMIC MANUFACTURING QUANTITY AND CONTROL LIMITS OF X-BAR CONTROL CHART

Traditional economic manufacturing quantity (EMQ) model assumes that the product of process is perfect. However, there possibly exists the defective product for the production process. Hence, we need to reconsider the method of statistical process control for the EMQ model. In this study, X-bar control chart is applied in the modified EMQ model. The minimum total cost of society including the cost of inventory control and quality cost need to be obtained in order to have the economic manufacturing quantity and the optimum parameters of control limits of X-bar control chart. The product quality is measured by adopting Taguchi's asymmetric quadratic quality loss function.