Repeatebility And Reproducibility

The average of the 30 ranges, R, is 5.20. From Appendix A, with Z = 30 (10 parts multiplied by 3 appraisers) and

W = 2 (2 trials), d2 is 1.128. The repeatability is

The average reading for appraiser A is 85.5, the average reading for appraiser B is 82.9, and the average reading for appraiser C is 88.9. To compute reproducibility, the average of the range between the appraiser with the smallest average reading (appraiser B in this example) and the appraiser with the largest average reading (appraiser C in this example) is needed.

Table  shows this data.

The average of the ranges, Xrange, is 7.015. From Appendix A, using Z = 1 and W = 3for 3 appraisers, is 1.91. The reproducibility is

The part variability is computed using the difference between the largest and smallest part measurement, where the average is taken for all parts and appraisers. This data is shown in Table.

The part with the largest average belongs to part 10, 103.97. The lowest average belongs to part 5, 59.72. This difference , 44.25, is Vp. From Appendix A, using Z = 1 and W =10 for 10 parts, d2 = 3.18. The part variability is