A Comparative Study of Cumulative Sum (CUSUM), Exponentially Weighted Moving Average (EWMA) and moving average control charts schemes in detecting process shift

Abstract

This study is aimed at designing Cumulative Sum(CUSUM),Exponentially Weighted Moving Average (EWMA) and Moving Average control chart and comparing their performances. The data used in thestudy are secondary data from the accident record office of the Federal Road Safety Commission (FRSC), Zone RS8 Command Headquarter, Offa Road, GRA, Ilorin, Kwara State, Nigeria for the period of January, 2000 to December, 2010.The CUSUM, the EWMA and the Moving Average control charts scheme were designed and used to study the rate of road crashes. Finally, the performances of the three designed control chart schemes were compared and it was observed that CUSUM chart scheme was more sensitive in detecting small shift in the process mean than either EWMA or Moving Average control chart schemes.