Question on MSA Requirement. Specifically: Are Gage Linearity, Bias and Stability test a requirement for PPAP submission. Or better yet are they a TS requirement? We calibrated most of our own hand tools, calipers, mics, indicators and set up the calibration to use the full range of the gage. We also conduct Gage R n R studies on all gages called out on the control plan. My struggle is that I can not find anything specific in the PPAP or MSA manuals that states a requirement for linearity, bias, or stability and at what interval they are to be done.