In the R&R process, the values are recorded and tabulated, the result is expressed as a percentage of the total tolerance. If the Low end of the tolerance is "0" and the high end of the tolerance is (-35) the absolute value of the total tolerance is "35". When the R&R Values are computed, squared and added together, then the square root is taken and divided by the tolerance, the resulting number is the gage R&R percentage.
10% is excellent, 11-30% is acceptable based upon the application, but should be closely monitored, and 31% or greater is unacceptable.