Reducing sampling costs in multivariate SPC with a double-dimension T2 control chart

► The DDT2 chart is a where the number of quality characteristics is variable. ► We find the distribution of a new statistical variable in order to compute the ARL. ► The parameters of the chart are optimized employing genetic algorithms. ► This chart detects process shifts very efficiently and with less cost. ► We compare its performance against the standard T2 control chart.