I-MR-R/S (Between/Within) Chart

Standard Deviations

  

The tables of standard deviations provide estimates of the different types of variation in the process.

·    The between standard deviation provides an estimate of the between-subgroup variation - that is the variation that exists from subgroup to subgroup.

·    The within standard deviation provides an estimate of the within-subgroup variation - that is the variation that exists within each subgroup

·    The between/within standard deviation provides an estimate of the total variation of the individual measurements. The total standard deviation is the combination of the between and within standard deviations

Example Output

Between         0.165737

Within          0.243244

Between/Within  0.294341

Interpretation

For the injection molding data, the estimate of the between standard deviation is 0.165737. The estimate of the within standard deviation is 0.243244. The estimate of the between/within standard deviation is 0.294341.