The process of analyzing gage variability is often highly structured, involving an examination of the gages themselves for sensitivity to temperature changes, magnetic fields, and other factors. These are the easy ones. The second area of variability has its source in gage operators themselves, who may have different levels of training, experience, fatigue, and even attitude.
We’ve all had the experience of keeping two or more versions of a document and—inevitably—sending or using the wrong one, uncertain of which is most current and accurate.