One-sided EWMA control chart for monitoring high yield processes
نویسنده
چکیده
A one-sided Exponential Weighted Moving Average (EWMA) control chart is introduced to monitor the fraction p of nonconforming products in high yield processes. It is designed to detect upward shifts of p screening the non-transformed geometric counts i.e. the number of conforming products between two nonconforming ones. Its algorithmic function is theoretically established and numerous performance measures are extracted using simulating methods. The efficiency and the performance superiority of the proposed one-sided EWMA control chart is verified through comparisons with a recently developed high yield chart, the simple two-sided EWMA control chart. Additionally, an algorithm of optimally designing the chart is developed and an optimality table for the most usual parameter values is adduced.
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