ABSTRACT
In very many cases, multivariate time indexed data are available for analysis. Yet it is rather standard for investigators to carry out their searches for Pareto glitches by control charting the data base one dimension at a time. A little modeling of the SPC situation gives us an indication that we are dealing with a rather special multivariate scenario. Multivariate tests can easily be constructed which give us the potential of substantial improvement over the one factor at a time approach.
