Overview for T² Chart

Use T² Chart to simultaneously monitor whether the process locations of two or more related variables are in control. This chart is the multivariate counterpart to the Xbar and Individuals charts.

For example, an engineer uses a T2 chart to monitor temperature and pressure in a plastic injection-molding process. Because temperature and pressure both affect the plastic strength, the engineer wants to monitor these variables at the same time.

The points vary randomly around the center line and are below the upper control limit. No trends or patterns are shown. The process location of the plastic product's strength is stable.

Where to find this control chart

To create a T2 chart, choose Stat > Control Charts > Multivariate Charts > .

When to use an alternate control chart

If variables are not correlated, use Xbar Chart or Individuals Chart.