Repeatability and reproducibility are the two components of precision in a measurement system. To assess the repeatability and reproducibility, use a gage R&R study (Stat > Quality Tools > Gage Study).
The ability of an operator to consistently repeat the same measurement of the same part, using the same gage, under the same conditions.
Operator 1 measures a single part with Gage A 20 times, and then measures the same part with Gage B.
The ability of a gage, used by multiple operators, to consistently reproduce the same measurement of the same part, under the same conditions.
Operators 1, 2, and 3 measure the same part 20 times with the same gage.