Gage R&R is intended to be a study to measure the measurement error in measurement systems.
We look at two components, gage variation (repeatability) and operator variation (reproducability).
The 10% rule tells us that If a measurement instrument does not discriminate to 10% of the part tolerance, the measurement instrument has no feasibility to measure the process variation and if the percent of tolerance consumed by the R&R does not exceed 10%, the measurement system is excellent.
The three elements of gage accuracy are linearity, accuracy and stability. Linearity is how the size of the part effects the accuracy of the measurement system.
Gage linearity is used to identify how accurate current measurements are through the expected range of the measurements.
It also gives answer to the question "Can we measure correctly all of the parts that have different sizes?
Linearity = slope * process variation
The closer the slope is to zero, the better the gage linearity.
In this case it would seem to give the answer that it doesn't really matter whether you have one or seperate R&R studies.
