The goal of a Gauge R&R study is to understand and quantify the sources of variability
present in the measurement process. It ensures you are not trying to control a process
to a degree that your measuring equipment cannot cope with.

The results of the statistical study are used to determine if the measurement process
requires improvement (poor repeatability), the measurement process requires control
(poor reproducibility) or for making compensations in the product being measured
(poor process control).

The two primary sources of variability that are evaluated in a Gauge R&R study are:

Repeatability - the variability associated with repeated measurements on the same part by one operator with the same gauge.

Reproducibility - the variability associated with different operators using the same gauge.