The multivariate exponentially weighted moving average (MEWMA) control chart is one of the best statistical control chart that are usually used to detect simultaneous small deviations on the mean of more than one cross-correlated quality characteristics. The economic design of MEWMA control charts involves solving a combinatorial optimization model that is composed of a nonlinear cost function ...

At present, due to the rapid development of domestic economy, environmental pollution problems are becoming increasingly serious, especially such as PM2.5 and PM10 caused by industrial emissions waste gas most urgent. The general linear profile model multivariate exponential weighted moving average control chart (MEWMA) is designed perform monitoring evaluating air quality index (AQI) in Tianji...

This paper proposes an exponentially weighted moving average scheme with variable sampling intervals for monitoring linear profiles. A computer program in Fortran is available to assist in the design of the control chart and the algorithm of the Fortran program is also given. Some useful guidelines are also provided to aid users in choosing parameters for a particular application. Simulation re...

We argue against the use of generally weighted moving average (GWMA) control charts. Our primary reasons are following: (1) There is no recursive formula for GWMA chart statistic, so all previous data must be stored and used in calculation each statistic. (2) The Markovian property does not apply to statistics, computer simulation determine limits statistical performance. (3) An appropriately d...

Overcrowding in emergency departments (EDs) is a primary concern for hospital administration. They aim to efficiently manage patient demands and reducing stress the ED. Detection of abnormal ED (patient flows) systems aids managers obtain appropriate decisions by optimally allocating available resources following attendance. This paper presents monitoring strategy that provides an early alert w...

Control charts are one of the tools in statistical process control widely used for monitoring, measuring, controlling, improving quality, and detecting problems processes various fields. The average run length (ARL) can be to determine efficacy a chart. In this study, we develop new modified exponentially weighted moving (EWMA) chart derive explicit formulas both two-sided ARLs p-order autoregr...

Quick detection of an assignable cause is necessary for process accuracy with respect to the specifications. The aim this study monitor time and magnitude processes based on unit-interval data. To end, maximum exponentially weighted moving average (Max-EWMA) control chart simultaneous monitoring event proposed. be precise, beta unit gamma distributions are considered develop Max-EWMA chart. cha...

Investigating the effect of measurement errors on control chart monitoring ratio two normal random variables is an important task to facilitate use this kind in practice. Moreover, a deep insight into problem can help practitioners find way reduce unexpected impacts performance. This paper provides study performance exponentially weighted moving average presence errors. We extend linear covaria...

Process monitoring through control charts is a quite popular practice in statistical process control. This study is planned for monitoring the process dispersion parameter using exponentially weighted moving average (EWMA) control chart scheme. Most of the EWMA dispersion charts that have been proposed are based on the assumption that the parent distribution of the quality characteristic is nor...