The dynamic T 2 chart for monitoring feedback-controlled processes
نویسندگان
چکیده
As manufacturing quality has become a decisive factor in global market competition, statistical quality techniques such as Statistical Process Control (SPC) are widely used in industry. With advances in information, sensing, and data collection technology, large volumes of data are routinely available in processes employing Automatic Process Control (APC) and Engineering Process Control (EPC). Although there is a growing need for SPC monitoring in these feedback-controlled environments, an effective implementation scheme is still lacking. This research provides a monitoring method, termed the dynamic T 2 chart that improves the detection of assignable causes in feedback-controlled processes.
منابع مشابه
The Effect of Estimation Error on Risk-adjusted Bernoulli GEWMA Control Chart in Multistage Healthcare Processes
Background and objectives: Risk-adjusted Bernoulli control chart is one of the main tools for monitoring multistage healthcare processes to achieve higher performance and effectiveness in healthcare settings. Using parameter estimates can lead to significantly deteriorate chart performance. However, so far, the effect of estimation error on this chart in which healthcare ...
متن کاملRobust 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 کاملNew 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 ord...
متن کاملMonitoring 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 کاملAn adaptive dimension reduction scheme for monitoring feedback-controlled processes
Detecting dynamic mean shifts is particularly important in monitoring feedbackcontrolled processes in which time-varying shifts are usually observed. When multivariate control charts are being utilized, one way to improve performance is to reduce dimensions. However, it is difficult to identify and remove non-informative variables statically in a process with dynamic shifts, as the contribution...
متن کامل