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...

ABSTRACTDhanty Store is a family start-up located in East Jakarta. It was initiated 2018, engaged retail with the main product form of women's clothing and accessories. One important processes Dhanty operations procurement process. Currently, request products according to their wishes without looking at sales data. This causes stock not well controlled. When there lot demand, sometimes Shops ru...

The exponentially weighted moving average (EWMA) X chart is effective in detecting small shifts. However, the EWMA X chart is not robust enough to prevent errors in estimating the process standard deviation or a changing standard deviation. To overcome this problem, Zhang et al. suggested the EWMA t chart in 2009. The existing optimal design of the EWMA t chart is based on the average run lengt...

Cumulative sum (CUSUM) and exponentially weighted moving average (EWMA) control charts are commonly used to detect small changes in the parameters of production processes. Recently, a new control structure was introduced, named as mixed EWMA–CUSUM control chart, which combined both charts. The current study provides a detailed comparison of these three types of control charts when the process p...

In this paper we propose the explicit formulas of Average Run Length (ARL) of Exponentially Weighted Moving Average (EWMA) control chart for Autoregressive Integrated Moving Average: ARIMA (p,d,q) (P, D, Q)L process with exponential white noise. To check the accuracy, the ARL results were compared with numerical integral equations based on the Gauss-Legendre rule. There was an excellent agreeme...