This article compares the effectiveness and robustness of nine typical control charts for monitoring the mean of a variable, including the most effective optimal and adaptive Sequential Probability Ratio Test (SPRT) charts. The nine charts are categorized into three types (the X¯ type, CUSUM...

This article proposes a new control chart (called the ABS SPRT chart) for Statistical Process Control (SPC) based on Sequential Probability Ratio Test (SPRT). This chart is able to monitor the mean and variance of a variable x simultaneously by inspecting the absolute sample shift x-[mu]0 (where...

This article presents a single CUSUM scheme (called the GCUSUM chart) for simultaneously monitoring the time interval T and magnitude X of an event. For example, a traffic accident may be considered as an event, and the total loss in dollars in each case is the event magnitude. Since the GCUSUM...

The and CUSUM control charts are used most widely for monitoring the mean of a quality characteristic x. This article studies the sample sizes and nCUSUM of these two charts in the domain of statistical design. However, the study takes the important sampling inspection cost (including the...

This study develops a procedure for the statistical design of the variable sampling intervals (VSI) multivariate exponentially weighted moving average (MEWMA) chart. The VSI MEWMA chart is compared with the corresponding fixed sampling interval (FSI) MEWMA chart, in terms of the steady-state...

This paper considers the interpretation of evidence from social experiments when persons randomized out of a program being evaluated have good substitutes for it, and when persons randomized into a program drop out to pursue better alternatives. Using data from an experimental evaluation of a...

On-line monitoring of quality characteristics is essential to limit scrap and rework costs due to bad quality in a manufacturing process. In several manufacturing environments, during production process data can be massively collected with high sampling rates and tight sampling frequencies. As a...

The double sampling (DS) X¯ chart detects small and moderate mean shifts quickly. Furthermore, this chart can reduce the sample size. The DS X¯ chart is usually investigated assuming that the process parameters are known. Nevertheless, the process parameters are usually unknown and are...

A modified median chart with estimated control limits is proposed for monitoring the mean value of a normal process. The estimates for the nominal process parameters used to set up the control limits in Phase I are the average of the sample medians and the average of the sample ranges of m...