Statistical control chart is one of the most powerful tools in quality control. It
was first developed by Walter Shewhart in 1920. It found widespread use in
World War II and since then it has gone through several modification. The main
drawback of multivariate charting schemes is their inability to identify which
variable was the source of the signal. The multivariate exponentially weighted
moving average (MEWMA) developed by Lowry et al. [2] is an example of a
multivariate charting scheme whose monitoring statistic is unable to determine
which variable caused the signal. In this paper, the run length performance of
multivariate exponentially weighted moving average (MEWMA) chart with
application is studied. Industry fertilizers is important one of the chemical
industries in Egypt, so that this work concerns the fertilizers industries quality
control, especially urea fertilizer with application on Delta fertilizer and
chemical industries which is considered on of the leading companies in the field
of fertilizer production in Middle east with application of multivariate quality
control procedures to achieve best one procedure for multivariate quality
control. |
