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...

Measurement error and autocorrelation often exist in quality control applications. Both have an adverse effect on the <italic>X¯</italic> chart's performance. To counteract the undesired effect of autocorrelation, we build-up the samples with non-neighbouring items, according to the time they were produced. To...

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...

On-line monitoring of process variability is strategic to achieve high standards of quality and maintain at acceptable levels the number of nonconforming items. Shewhart control charts are the simplest Statistical Process Control (SPC) procedure to achieve this goal. An efficient implementation...

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...

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 EWMA chart for the standard deviation is a useful tool for monitoring the variability of a process quality characteristic. The performance of this chart is usually evaluated under the assumption of known parameters. However, in practice, process parameters are estimated from an in-control...