The evaluation of a gauging instrument's accuracy by determining whether its measurements are repeatable (there is close agreement among a number of consecutive measurements of the output for the same value of the input under the same operating conditions) and reproducible (there is close agreement among repeated measurements of the output for the same value of input made under the same operating conditions over a period of time).
Gauge R&R measures the amount of variability induced in measurements by the measurement system itself, and compares it to the total variability observed to determine the viability of the measurement system. * Repeatability: The variation in measurements taken by a single person or instrument on the same item and under the same conditions. * Reproducibility: The variability induced by the operators. It is the variation induced when different operators (or different laboratories) measure the same part.