In a gauge R&R study, a low R&R percentage relative to tolerance indicates what?

In a gauge R&R study, a low R&R percentage relative to tolerance indicates what?

• A. It indicates the measurement system has low repeatability.
• B. It indicates the measurement system has poor precision.
• C. It indicates the measurement system has good repeatability and reproducibility.
• D. It indicates the process is defect-free.

Answer: (C)

The key idea is that gauge R&R tells us how much of the observed variability comes from the measurement system itself. When the R&R percentage relative to tolerance is low, the measurement error is small compared to the allowable tolerance. In a gauge R&R study, repeatability looks at how much measurements vary when the same operator uses the same instrument on the same part, while reproducibility looks at how much measurements vary when different operators or setups measure the same part. If the R&R portion is small, most of the variation you see is due to the parts, not the measurement process, so the measurement system is reliable—showing good repeatability and good reproducibility. This helps ensure that the gauge isn’t masking or exaggerating true part variation. It does not mean the process is defect-free, and a high R&R would indicate poorer precision.

The key idea is that gauge R&R tells us how much of the observed variability comes from the measurement system itself. When the R&R percentage relative to tolerance is low, the measurement error is small compared to the allowable tolerance. In a gauge R&R study, repeatability looks at how much measurements vary when the same operator uses the same instrument on the same part, while reproducibility looks at how much measurements vary when different operators or setups measure the same part. If the R&R portion is small, most of the variation you see is due to the parts, not the measurement process, so the measurement system is reliable—showing good repeatability and good reproducibility. This helps ensure that the gauge isn’t masking or exaggerating true part variation. It does not mean the process is defect-free, and a high R&R would indicate poorer precision.