On Some Extensions to EWMA and CUSUM Charts to Monitor Process Parameters

Control charts are very popular tools that are used to monitor stability of process parameters in order to detect unfavorable variations in location and variability parameters. These charts have two major classifications namely memory and memory less. It is always required to design new charting structures for effective monitoring of process parameters. In this project we propose and investigate some new CUSUM and EWMA control charts based on extended use of sampling schemes and utilization of auxiliary information for efficient phase II process monitoring. In addition, some efficient techniques such as the implementation of run rules and fast initial response will be covered in the proposed designs. The design parameters of the proposals will be derived under correlated setups for the monitoring of process parameters. The properties of these charting structures will be evaluated in terms of average run length (ARL), extra quadratic loss (EQL) and some other related measures. The performance abilities of these charts will be compared with each other and also with some existing counterparts. The proposed charts will also be applied to real datasets from different disciplines such as in engineering, health care, and analytical laboratories.