X-bar S Chart

Control chart pair monitoring process average and standard deviation, typically for larger subgroup sizes.

Examples

01The tablet line uses an X-bar S chart because each sample contains 15 tablets, too many for a reliable range calculation.
02The supplier's X-bar S charts are reviewed quarterly to see whether the standard deviation is getting smaller after improvements.
03When the S part of the X-bar S chart rises while the average stays stable, the team checks for uneven powder flow in the hopper.