What are gage R&R and Wheeler's EMP studies?

Gage R&R studies and Wheeler's EMP studies assess the repeatability and reproducibility of a measurement process. These assessments help you to investigate the precision of a measurement system and identify opportunities for improvement.

Repeatability and reproducibility are the two components of precision in a measurement system. For example, several operators measure the diameter of screws to ensure that they meet specifications. A gage study (Stat > Quality Tools > Gage Study) indicates whether the operators are consistent in their measurements of the same part (repeatability) and whether the variation between operators is consistent (reproducibility). For more information on repeatability and reproducibility, go to What are repeatability and reproducibility?.

Gage R&R studies and Wheeler's EMP studies are similar. The collection of subgroups of measurements by part and operator are common to both studies. The results for both studies include assessments of the stability of the measurements. The principal difference in the methods is how they determine whether a measurement system is acceptable. For more information on how the studies determine whether a measurement system is acceptable, go to Is my measurement system acceptable?.