is the most tacit. The sound of a nut being driven on a Corolla door panel has a specific frequency. A stripped thread sounds different. Toyota has never formalized this as a codec, but it is taught through minarai (apprenticeship by watching).
ensures that every tool has a “home shape.” Toyota’s famous sagyou hyoujun (standardized work) images are not just instructions—they are templates for matching perception. toyota katashiki code