Reproducibility Range Chart Calculations

Note: This chart is used when (2  Number of Appraisers  10)

Plotted Statistic:

The difference between the largest and smallest Appraiser average for each part.

Center Line:

The Average Range.

UCL , LCL (Upper and Lower Control Limit)

where

d3 is based on a subgroup size m = the number of Appraisers,

d2* is based on a subgroup size m = the number of Appraisers and g = the number of parts.

Notes:

1. Some authors, including AIAG, refer to the quantity (1+3(d3 / d2*)) as D4 , and (1-3(d3 / d2*)) )) as D3

2. Table for d2* values may be found in A.J. Duncan, Quality Control and Industrial Statistics, 1965, Third Edition Richard D. Irwin, Homewood, Illinois. Table D3, pg. 910.

See also:

Reproducibility X-Bar Chart Calculations

Reproducibility Sigma Chart Calculations

Learn more about the Quality Improvement principles and tools for process excellence in Six Sigma Demystified (2011, McGraw-Hill) by Paul Keller, or his online Green Belt certification course ($499).