Control charts usually present a graphic display of process stability and/or instability with time, from which the you can determine mean and standard deviation.

This example uses the GPLOT procedure and the DATA step function PROBNORM to plot operating characteristic (OC) curves for charts with 3 limits. An OC curve is plotted for each of the subgroup samples ...

Can using a basal body temperature chart help you get a positive pregnancy test soon? Maybe! Here's how this handy tool helps some people track fertility.

When you are working with subgrouped data, it can be helpful to accompany a cusum chart for means with a Shewhart s chart for monitoring the variability of the process. This example creates this ...