X̄-S Control Chart Online
Online X̄-S (average and standard deviation) control chart. Ideal for monitoring processes with large subgroups (n > 10); automatically calculates UCL/CL/LCL and flags out-of-control points.
When should I use X̄-S instead of X̄-R?
When the subgroup size n > 10, the range method loses efficiency and the standard deviation method should be used. The X̄-S chart is more accurate for large subgroups.