Mistake-proofing — designing processes and devices so that errors are either impossible to make or immediately detectable. shigeo-shingo developed poka-yoke as an extension of jidoka, moving beyond detection (catching defects) to prevention (making defects impossible). Examples range from simple (a jig that only accepts parts in the correct orientation) to sophisticated (sensors that verify assembly completeness before a part moves to the next station). Shingo's original term was "baka-yoke" (fool-proofing), but he renamed it to "poka-yoke" (mistake-proofing) after a worker objected. The philosophy — that errors are natural and the system should prevent them from becoming defects — is the opposite of the Western approach of blaming workers for mistakes. Described in zero-quality-control.