Anastasopoulou Maria, Rakitzis Athanasios C
Department of Statistics and Actuarial-Financial Mathematics, University of Aegean, Karlovasi, Greece.
J Appl Stat. 2020 Sep 16;49(3):553-573. doi: 10.1080/02664763.2020.1820959. eCollection 2022.
In this work, we develop and study upper and lower one-sided EWMA control charts for monitoring correlated counts with finite range. Often in practice, data of that kind can be adequately described by a first-order binomial or beta-binomial autoregressive model. Especially, when there is evidence that data demonstrate extra-binomial variation, the latter model is preferable than the former. The proposed charts can be used for detecting upward or downward shifts in process mean level. Practical guidelines concerning the statistical design of the proposed charts are given, while the effect of the extra-binomial variation is investigated as well. Comparisons with existing control charting procedures are also provided. Finally, an illustrative real-data example is also given.
在这项工作中，我们开发并研究了用于监测有限范围相关计数的单边上下EWMA控制图。在实际中，这类数据通常可以用一阶二项式或贝塔-二项式自回归模型进行充分描述。特别是，当有证据表明数据呈现超二项式变异时，后一种模型比前一种更可取。所提出的控制图可用于检测过程均值水平的向上或向下偏移。给出了关于所提控制图统计设计的实用指南，同时也研究了超二项式变异的影响。还提供了与现有控制图程序的比较。最后，给出了一个说明性的实际数据示例。
