Repeatability and reproducibility in measurement systems

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).
Repeatability
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 solid line is the measurements from Gage A. The dashed line is the measurements from Gage B. Gage A has less variation, so it is more repeatable than Gage B.

Reproducibility
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.

The three lines are the measurements from Operator 1, 2, and 3. The variation in average measurements between Appraisers 1 and 2 is much less than the variation between Appraisers 1 and 3. Therefore, the gage's reproducibility is too low.

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