A gage R&R is a method of evaluating several potential sources of variation in a measurement system. The typical gage R&R quantifies the variation due to differences between parts, between operators, and between units treated identically (gage variation).

The idea is that the variation between operators and the gage variation should be small compared to the total variation observed. If it is not, you can use the gage R&R to determine whether you need to retrain your operators or improve your gage, or both.

If you haven't already, I strongly suggest you purchase a copy of the AIAG Measurement System Analysis Reference Manual, available at

http://www.aiag.org/
Only $11 for non-members. It is well written.

I also strongly suggest you invest in statistical software capable of analyzing the results properly. Your best bets are MINITAB, StatGraphics, and JMP. I prefer MINITAB.

Ken K.