高质量过程控制技术的比较研究与分析

随着质量改进活动的不断开展,现代制造过程中的不合格项在逐渐降低。在这种情况下,常规的休哈特型计数控制图往往是失效的。为了监控高质量的过程运行,一种方法是采用累计合格品计数(CCC)图;另一种方法是采用几何Q图,本文首先分析了这两种控制图的基本原理;进而以平均链长(ARL)和探测过程发生漂移的概率为准则,系统分析和比较了这两种控制图的性能,仿真结果表明,在大多数情况下,这两种控制图具有相似的性能;最后,通过实例说明了这两种控制图的应用,并给出了若干建议。

Comparison and Analysis for High Quality Processes Monitoring Techniques

With the development of quality improvement programs,many production processes today are producing a very low level of nonconforming items.In this case,conventional Shewhart type attribute control charts are not applied effectively in practice.In order to monitor high quality processes,two al- ternative techniques are proposed: one is a cumulative count of conformance(CCC)chart,the other is geometric Q chart.In this paper,we first analyze basic principal of both CCC chart and geometric Q chart,which is based on the geometric distribution.Then we compare the performance by using average run length(ARL)and the probability of detecting a shift in the observations after a shift occurs.Simu- lation results show that in most cases CCC chart and geometric Q chart are of the similar performance. After that an example from practice is presented.And finally,some suggestions are given in conclusion.