I was fortunate enough that the previous company I worked for purchased a ROBOCRIB. The automated tracking made it easy to identify how often a gage is used, so adjustments to frequency based on cycles/usage were easily managed. Having first hand knowledge of the manufacturing environment and the conditions most gages are exposed to most often seemed paramount for determining the initial frequency, which may be more than the typical 1 year, Third party calibration certification coverage.
Purchasing gages with longform certs by an accredited Lab was the first step so no initial calibration was required - just get them in the registry and apply the standardized frequency per current practice.
The most reliable means for determining frequency was based in understanding how dirty the environment was and how often adjustments had to be made within gage families for specific work groups. For example, micrometers needed frequent maintenance when they were used constantly for inspecting Rare Earth Materials in the Grinding Cells. Frequent loading and unloading of parts on machines meant very frequent in-process use with a lot of handling in dirty conditions. In these cases, Micrometers were calibrated every 6 months with frequent functional checks on the shop floor. In the CNC cells handling alloys, annual calibration of Micrometers and Calipers was suitable, even with constant use. Same with Calipers and test indicators etc..
Another thing that helped was standardizing calibrations more easily by eliminating employee-owned gages, and issuing the same models across the board to individuals for Assembly, Manufacturing and Inspection. Not only for a more apples to apples inspection comparison, but more consistency in calibration frequencies and very predictable calibrations with only rare, minor out of tolerance conditions popping up.
This thread can go on and on and I love the read. I'll stop here.
