X-charts display subgroup means (averages)
R-charts display subgroup ranges (maximum – minimum)
S-charts display subgroup standard deviations
Levey-Jennings charts show a process mean with control limits based on a long-term sigma. The control limits are placed at 3s distance from the center line. The standard deviation, s, for the Levey-Jennings chart is calculated the same way standard deviation is in the Distribution platform.

Help created on 9/19/2017