New phase II control chart for monitoring ordinal contingency table based processes

In some statistical process monitoring applications, quality of a process or product is described by more than one ordinal factor called ordinal multivariate process. To show the relationship between these factors, an ordinal contingency table is used and modeled with ordinal log-linear model. In this paper, a new control charts based on ordinal-normal statistic is developed to monitor the ordinal log-linear model based processes in Phase II. Performance of the proposed control chart is evaluated through simulation studies and a real numerical example. In addition, to show the efficiency of ordinal-normal control chart, performance of the proposed control chart is compared with an existing Generalized-p chart. Results show the better performance of the proposed control chart in detecting the out-of-control condition.