In this paper, comparing between two important procedures: Multivariate Exponentially Weighted Moving Average (MEWMA) quality control chart and Hotelling's T^2 quality control chart. The first procedure MEWMA is an example of a multivariate charting scheme whose monitoring statistic is unable to determine which variable caused the signal. The average run length (ARL) performance of MEWMA chart is studied. The second procedure is Hotelling's T^2 quality control chart is used to determine whether or not the process mean vector for two or more variables is in-control. It is allowing us to simultaneously monitor whether two or more related variables are in control, and it is shown that multivariate quality control chart do not indicate which variables cause the out-of-control signal so that the interpretation of the out-of-control signal. Also, in this paper develops the multivariate quality control charts of the out of-control signal, this will be maintained by making and industrial application on the fertilizers factory. It is important to know that this factory has a special department for quality control, in order to maintain International Standardization Organization (ISO). |
