A Statistical Process Control (SPC) chart is a graph that shows how data changes over time. It’s a tool used to monitor process performance and improve quality.  A control chart always has a central line for the average, an upper line for the upper control limit, and a lower line for the lower control limit. These lines are determined from historical data. By comparing current data to these lines, you can draw conclusions about whether the process variation is consistent (in control) or is unpredictable (out of control, affected by special causes of variation).  This can be used in a variety of applications such as determining if a process is stable, predicting the expected range of outcomes, or analyzing patterns of process variation.

To change the number of standard deviations used away from the mean, in Grapher, select the Control limits plot and in the Property Manager, on the Plot tab, adjust the Box edges and Whiskers #deviations from mean value.

Industry Focus: Healthcare, Manufacturing
Graph Features: Box, Line, Scatter