The sixpack function lets us generate six charts to give the control charts and capability in a single page. This forms a useful overview of the stability of our process and how well we fit to customer specifications. It also helps to avoid the common error of trying to fit specifications to control charts.

The example we will be using looks at the fill volumes of syringes. We check the capability of the fill volumes against a target fill volume of 15 ml and specifications of 14.25 ml and 15.75 ml.

Within the worksheet, 40 results are collected per day, taken at the rate of five samples per hour. The data is presented as these subgroups across rows; each row representing the results of the five samples within that hour.