合成控制图

Synthetic Control Charts

质量管理中广泛使用的休哈特 X 控制图 ,对发现工序均值大偏移有效 ,但对小偏移却不敏感 ,np控制图情况类似。现提出 2种合成控制图 :合成 X- CRL控制图与合成 np - CRL控制图。结果发现工序小到中等变化的平均链长大约只有普通 X 控制图与 np控制图的一半 ,明显地优于 Cusum控制图和 EWMA控制图。

In quality control, Shewhart control charts are widely used because they are efficient for large mean shift. But for small or moderate mean shift, they are less sensitive. Similar phenomenon occurs in np control charts. This research proposed two synthetic control charts: a synthetic -CRL control chart and a synthetic np-CRL control chart. The synthetic control charts consistently produced shorter out-of-control average run lengths than the charts and the np charts by nearly half for small or moderate shift. They are better than Cusum control chart and EWMA control chart.