This paper proposes an economic model for the synthetic chart. The synthetic chart is an integration of the X chart and the CRL chart. A simplified algorithm to obtain the optimal parameters of the synthetic chart which minimizes the expected cost function is introduced. Numerical examples based on different values of input parameters are given, and sensitivity analyses of the parameters are pe...

In statistical process control (SPC), the ratio of two normal random variables (RZ) is a valuable indicator to be taken as charting statistic. this work, we propose triple exponentially weighted moving average (TEWMA) chart for monitoring RZ. Additionally, variable sampling interval (VSI) strategy has been adopted different charts by researchers. With application strategy, VSI-TEWMA-RZ then dev...

An effective control scheme can be instrumental in increasing productivity and reducing cost. While facing an outlier-existing process, using the mean ( X ) control chart and the range (R) control chart for monitoring the process mean and variance will lead to high level false alarms. Recently, some median ( X~ ) control charts, such as the X~ Shewhart control chart, the exponentially weighted ...

In this research, an iterative approach is employed to analyze and classify the states of univariate quality control systems. To do this, a measure (called the belief that process is incontrol) is first defined and then an equation is developed to update the belief recursively by taking new observations on the quality characteristic under consideration. Finally, the upper and the lower control ...

Some of the most widely-investigated control charting techniques for autocorrelated data are based on time series residuals. If the mean shift in the autocorrelated process is a sudden step shift, the resulting mean shift in the residuals is time varying and has been referred to as the fault signature. Traditional residual based charts, such as a Shewhart, CUSUM, or EWMA on the residuals, do no...

In industrial production, the exponentially weighted moving average scheme is widely used to monitor shifts in product quality, especially small-to-moderate shifts. this paper, we propose a modified one-sided EWMA for Type I right-censored Weibull lifetime data detecting scale parameter with shape fixed. A comparative analysis existing cumulative sum and results from literature provided. The ze...

Recently, monitoring the process mean and variance simultaneously by using a single chart has drawn more and more attention. In this paper, we propose a new single chart that integrates the EWMA procedure with the generalized likelihood ratio (GLR) test statistics for jointly monitoring both the process mean and variance. It can be easily designed and constructed, and its average run length can...