What is reproducibility and how is it measured in a gage R & R study? The reproducibility measured by a gage R & R study refers to the variability in measurement which results from the irregularities of the operator. Reproducibility is tested by having multiple individuals measure the same part using the same gage. In this way, a gage R & R study can adequately determine if there is variability due to the individuals measuring the product, rather than the measurement process or equipment itself. The reproducibility is necessary to know how much variation results when different operators use the same equipment. Just as it is important to know that your equipment is functioning well, it is necessary to know how individuals are impacting the measurement process of a larger manufacturing system.