本研究提出製程上量測值發生誤差時經濟管制圖的建構方法。建構的管制圖分別討論有量測誤差及無量測誤差之情況。數值分析結果發現量測誤差明顯影響管制圖偵測力，且有量測誤差的管制圖偵測力更差且成本更高。是以量具之校正非常重要。另外，當有量測誤差時，小偏移量之偵測，EWMA管制圖仍優於區域X-bar管制圖。 The presence of imprecise measurement may serious affect the efficiency of process control and production cost. A cost model is derived to determine the design parameters of the economic asymmetric .Xbar. and S control charts excluding or including measurement errors, respectively. The effects of imprecise measurement to the performance of the economic asymmetric .Xbar. and S control charts and production cost are examined for the case where the process mean and process standard deviation may change. Application of the proposed control charts is demonstrated through an example. Numerical examples illustrate the effects of imprecise measurement on the design parameters of the proposed control charts. It shows that the imprecision measurement may seriously affect the ability of the proposed control charts, which include measurement errors, to detect process disturbances quickly, change the sampling frequency, and increase the production cost compared to the proposed control charts excluding measurement errors. Besides, the effects of measurement error on the EWMA control chart and Zone X-bar control chart, which detects the small shift of process mean, is studied.
