There are variations on the standard X-bar & R Charts which may be more appropriate in certain manufacturing situations.
Variations on the R Chart include:
- R – Monitors range within a subgroup.
- MR – Monitors range between subgroups.
- RD – Monitors range of parameter difference.
- s – Monitors the process standard deviation.
Variation on the Chart include:
- X-Bar – Monitors the process location with subgroups.
- IX – Monitors single samples, not subgroups.
- X-Bard – Monitors the difference between the subgroup average and the historical process average or the nominal of the specification.
- IXd – Monitors the difference between the individual value and the historical process average or the nominal of the specification.