BS ISO 7870-6:2016将EWMA控制图作为一种统计过程控制技术用于 检测过程中的微小变化。它可以更快地检测小到中等的换档 在这个过程中，平均数是多少。在这个图表中，过程平均值以指数加权的方式进行评估 所有先前样本均值的移动平均值。EWMA按几何递减顺序加权样本 因此，最近的样本权重最高，而最远的样本贡献最大 几乎不依赖于平滑参数（λ）。注1:基本目标与ISO 7870-2中描述的休哈特控制图相同。在极少数情况下，休哈特控制图的应用是值得的，这些情况下，生产速度缓慢，取样和检验程序复杂且耗时，测试费用昂贵，且存在安全风险。 注2:变量控制图可用于从生产线获取的单个观察值， 而不是观察样本。当测试多个观测值的样本时，这有时是必要的 太贵、不方便或不可能。例如，客户投诉或产品的数量 报税表只能按月提供；然而，人们希望通过图表来检测这些数字的质量 问题。这些图表的另一个常见应用发生在自动测试设备检查生产的每一个单元的情况下。在这种情况下，人们通常主要感兴趣的是检测产品质量的微小变化（例如，由于机器磨损导致的质量逐渐恶化）。交叉引用:ISO 7870-1ISO 7870-2ISO 7870-4ISO 3534-1ISO 3534-2ISO 7870-3ISO 7870-5ISO 7873:1993NF X06- 031-1NF X06-031-2NF X06-031-3NF X06-031-4购买本文件时可用的所有现行修订版均包含在购买本文件中。

BS ISO 7870-6:2016 covers EWMA control charts as a statistical process control technique to detect small shifts in the process mean. It makes possible the faster detection of small to moderate shifts in the process average. In this chart, the process average is evaluated in terms of exponentially weighted moving average of all prior sample means. EWMA weights samples in geometrically decreasing order so that the most recent samples are weighted most highly while the most distant samples contribute very little depending upon the smoothing parameter (λ).NOTE 1 The basic objective is the same as that of the Shewhart control chart described in ISO 7870-2.The Shewhart control chart's application is worthwhile in the rare situations whenproduction rate is slow,sampling and inspection procedure is complex and time consuming,testing is expensive, andit involves safety risks.NOTE 2 Variables control charts can be constructed for individual observations taken from the production line, rather than samples of observations. This is sometimes necessary when testing samples of multiple observations would be too expensive, inconvenient, or impossible. For example, the number of customer complaints or product returns may only be available on a monthly basis; yet, one would like to chart those numbers to detect quality problems. Another common application of these charts occurs in cases when automated testing devices inspect every single unit that is produced. In that case, one is often primarily interested in detecting small shifts in the product quality (for example, gradual deterioration of quality due to machine wear).Cross References:ISO 7870-1ISO 7870-2ISO 7870-4ISO 3534-1ISO 3534-2ISO 7870-3ISO 7870-5ISO 7873:1993NF X06-031-1NF X06-031-2NF X06-031-3NF X06-031-4All current amendments available at time of purchase are included with the purchase of this document.