Westgard J O, Groth T, Aronsson T, Falk H, de Verdier C H
Clin Chem. 1977 Oct;23(10):1857-67.
When assessing the performance of an internal quality control system, it is useful to determine the probability for false rejections (pfr) and the probability for error detection (ped). These performance characteristics are estimated here by use of a computer stimulation procedure. The control rules studied include those commonly employed with Shewhart-type control charts, a cumulative sum rule, and rules applicable when a series of control measurements are treated as a single control observation. The error situations studied include an increase in random error, a systematic shift, a systematic drift, and mixtures of these. The probability for error detection is very dependent on the number of control observations and the choice of control rules. No one rule is best for detecting all errors, thus combinations of rules are desirable. Some appropriate combinations are suggested and their performance characteristics are presented.
在评估内部质量控制系统的性能时，确定错误拒收概率（pfr）和错误检测概率（ped）是很有用的。这里通过计算机模拟程序来估计这些性能特征。所研究的控制规则包括那些常用于休哈特型控制图的规则、累积和规则以及当一系列控制测量被视为单个控制观测值时适用的规则。所研究的误差情况包括随机误差增加、系统偏移、系统漂移以及这些情况的混合。错误检测概率非常依赖于控制观测值的数量和控制规则的选择。没有一个规则对检测所有误差都是最佳的，因此规则组合是可取的。文中提出了一些合适的组合并展示了它们的性能特征。
