Summary: | 碩士 === 國立臺北大學 === 統計學系 === 106 === It is important to improve the stability of the process and the quality of the product in the production process. Control charts have been widely used in statistical process control because of their operational simplicity. In order to reduce the variation in the process, Shewhart proposed the concept of the control chart in 1920. Many adaptive charts have been proposed to improve the performance of control charts, such as two-stage control chart, CUSUM chart and EWMA control chart.
Traditional control charts are only monitored with a performance variable. However, it takes a higher cost to monitor the process in some cases. It is more economical and efficient to use surrogate variables which are highly correlated with performance variables. In this thesis, we consider a robust model for economic design of two-stage control charts that using performance variable and surrogate variable in alternating fashion. We will compare the efficiency of the process and the cost reduction of monitoring of this robust model with that of the model in the reference by using the maximum expected net income and the optimum values of design parameters.
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