关键词: 控制图经济设计, SSX控制图, XR控制图, 平均调整时间

Abstract: Aiming at the occurrence time of assignable cause follows exponential distribution,a Supplementary Sample X(SSX) control chart was used to monitor the mean value and variance of process quality feature,and the economic performance of SSX control chart was researched.The cost function model for implementation of SSX control chart was constructed,and the pattern search algorithm was used to optimize this model.Thus the decision variables,Average Adjusted Time to Signal (AATS) and cost of SSX control chart were obtained,and the economic performance between SSX,XR and Variable Sampling Interval (VSI) XR control chart was compared.The simulations revealed that the average adjustment time and monitoring costs of SSX chart were reduced obviously than XR,and SSX control chart was better than VSI XR under most cases of shifts.A sensitivity analysis of the model was performed,and the results showed that the sampling intervals and control limits of SSX control chart were affected by the parameters in the cost function.

Key words: economic design of control chart, supplementary sample control chart, XR control chart, average adjusted time to signal