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 factors 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.
The effect of parameter estimation on Phase II control chart performance in monitoring financial GARCH processes with contaminated data
The application of control charts for monitoring financial processes has received a greater focus after recent global crisis. The Generelized AutoRegressive Conditional Heteroskedasticity (GARCH) time series model is widely applied for modelling financial processes. Therefore, traditional Shewhart control chart is developed to monitor GARCH processes. There are some difficulties in financial su...متن کامل
Monitoring Financial Processes with ARMA-GARCH Model Based on Shewhart Control Chart (Case Study: Tehran Stock Exchange)
Financial surveillance is an interesting area after financial crisis in recent years. In this subject, important financial indices are monitored using control charts. Control chart is a powerful instrument for detecting assignable causes which is considerably developed in industrial and service environments. In this paper, a monitoring procedure based on Shewhart control chart is proposed to mo...متن کامل
Robust economic-statistical design of the EWMA-R control charts for phase II linear profile monitoring
Control charts are powerful tools to monitor quality characteristics of services or production processes. However, in some processes, the performance of process or product cannot be controlled by monitoring a characteristic; instead, they require to be controlled by a function that usually refers as a profile. This study suggests employing exponentially weighted moving average (EWMA) and range ...متن کامل
Previously, quality control and improvement researchers discussed multivariate control charts for independent processes and univariate control charts for autocorrelated processes separately. We combine the two topics and propose vector autoregressive (VAR) control charts for multivariate autocorrelated processes. In addition, we estimateAR(p) models instead ofARMAmodels for the systematic cause...متن کامل
A one-sided Exponential Weighted Moving Average (EWMA) control chart is introduced to monitor the fraction p of nonconforming products in high yield processes. It is designed to detect upward shifts of p screening the non-transformed geometric counts i.e. the number of conforming products between two nonconforming ones. Its algorithmic function is theoretically established and numerous performa...متن کامل
دوره 12 شماره Special issue on Statistical Processes and Statistical Modeling
صفحات 15- 34
تاریخ انتشار 2019-01-21
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