The synthetic chart combined with an chart (Synthetic- chart) signals when a sample point falls beyond the control limits or when a second point, not far from the first one, falls beyond the warning limits, no matter whether ...

Control charts are designed to detect assignable causes that may occur in production processes. They are very simple operationally; however, this operational simplicity, that is, taking samples of fixed size n at regular ...

Traditionally, an (X) over bar chart is used to control the process mean and an R chart is used to control the process variance. However, these charts are not sensitive to small changes in the process parameters. The ...

In this article, we propose the S chart with variable charting statistic to control the covariance matrix as an alternative to the use of the bivariate |S| chart and the trivariate VMAX chart. As usual, samples are regularly ...

The usual practice in using a control chart to monitor a process is to take samples of size n from the process every h hours This article considers the properties of the XBAR chart when the size of each sample depends on ...

This article proposes two Shewhart charts, denoted np(xy) and np(w) charts, which use attribute inspection to control the mean vector ((x); (y)) of bivariate processes. The units of the sample are classified as first-class, ...