Sort CNC Signals: Common vs Special Cause

Sort each signal by the most likely first interpretation before action. Likely common-cause variation Likely special-cause signal Check measurement system first Surface finish readings move slightly within the established process band across the whole shift OD readings drift upward in one direction after part 40 with the same insert Two operators disagree by half the tolerance on the same bore using the same gage A sudden diameter jump appears immediately after the part stop was replaced Three repeated readings on the same part spread more than the process movement Part-to-part readings scatter randomly around nominal with no trend or rule…

Sign up free — one personalized lesson every day, matched to your role and goals.

Already have an account? Sign in