Revision Date: 2005-09-02
GAGEpack 4.0 and GAGEpack 5.0 up to release 34 do the calculations for the R&R percentages consistently with the 2nd edition of the MSA manual. The percentages for EV, AV, R&R and TV are consistent with the calculations in the 3rd edition of the MSA manual. The difference in the MSA calculations are in the examples worked-through on pages 57-58 of the 2nd edition and pages 113-114 of the 3rd edition. (This would be true of all the similar examples in either edition.) The values for K1, K2 and K3 in the 2nd edition (page 58) are divided by 5.15 in the 3rd edition (page 114). This makes the calculated values on the left side of page 114 smaller than the values calculated on the left side of page 58 by a factor of 5.15. However, the percentages on the right hand side of pages 114 and those on the right hand side of page 58 will be the same, since multiplying the top and bottom by the same number does not affect the ratio (or percentage) values.
In GAGEpack 5.0.36, the calculations for EV, AV, PV and R&R were changed to reflect the new K values. Since all of the values (including TV) were reduced by a factor of 5.15, all of the percents for EV, AV, R&R and PV are correct when the study parameters method is used. However, when tolerances (specifications) or process parameters are used, the left hand side needs to be multiplied by 5.15 (or alternatively by 6) in order for the percentages to be correctly calculated. This was not done in release 5.0.36, but was corrected in release 5.0.39. Note: this value can be adjusted (generally it should only be adjusted to 6.0 to represent 6 sigma) by editing the value of NormalSigma in the file GPWIN50.INI.
Ref # 981
