One-Sided and Two-Sided New Modified EWMA control chart for Detecting Increases in Process Mean

The main objective of this research is to introduce a new type of control chart, the New Modified EWMA control chart, to detect changes in the process of the average value by studying both one-sided and two-sided control charts. The model studied in this research is the moving average process, or MA(q), with an exponential distribution of residuals. The explicit formula for the average run length of the modified EWMA control chart using the integral equation method to prove the average run lenis are presented. The results of the research found that the average run length obtained has high accuracy and is fast in finding the value when compared to the numerical integral equation method. In this research, several models, such as MA(1), MA(2), and MA(3) processes, were simulated at different parameter levels. In addition, it has been applied to real environmental data, including PM2.5 and PM10 data in Thailand. If the control limits for PM2.5 and PM10 are exceeded, it can be used to identify a potential environmental issue, enabling authorities to investigate the situation and take action before the air quality gets worse.