A variable sampling interval Shewhart control chart for monitoring the coefficient of variation in short production runs
研究了一种可变抽样间隔的休哈特控制图，用于在短生产批次中监控变异系数，推导了截断平均报警时间公式，并与固定抽样率图表进行了性能比较，通过工业数据示例展示应用。
Monitoring the coefficient of variation (CV) allows process monitoring to be performed when both the process mean and the standard deviation are not constant but, nevertheless, proportional. Until now, few research papers have investigated the monitoring of the CV in a short production run context. This paper investigates the design and implementation of a Variable Sampling Interval Shewhart control chart to monitor the coefficient of variation in a short production run context. Formulas for the truncated average time to signal are derived and a performance comparison is carried out with a Fixed Sampling Rate Shewhart chart monitoring the CV. An example illustrates the use of this chart on real industrial data.