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 proposes a multivariate EWMA scheme that is alternative to the traditional EWMA-M. The distribution of the chart statistic is derived from Box quadratic form and the sensitivity of the chart is examined. The average run lengths of the M-EWMA scheme are numerically computed with the...