poke yoke

Error Proofing, Mistake Proofing, or in Japanese Poka-Yoke.  Shigeo Shingo developed Poka-Yoke while working for Toyota. Poka-Yoke is first and foremost the prevention of an error before it could have occurred. That is, you cannot do it wrong. It can only be done one way. A three-prong plug can only be inserted one way. Baring [...]