Poka-yoke, a Japanese term meaning "mistake-proofing," refers to any mechanism in a manufacturing process that helps prevent human errors or makes them immediately obvious. Developed by Shigeo Shingo as part of the Toyota Production System, poka-yoke devices range from simple physical fixtures to sophisticated sensor-based detection systems.
Poka-yokes fall into two categories: prevention devices that make errors physically impossible (a fixture that only accepts a part in the correct orientation, a connector that only plugs in one way) and detection devices that immediately alert the operator when an error occurs (a sensor that stops the machine if a component is missing, a scale that verifies the correct number of fasteners were installed).
In manufacturing, poka-yoke is most valuable at operations where errors are common, costly, or safety-critical. Digital poka-yoke extends the concept to software: work instruction systems that require scan verification of components before assembly, inspection systems that prevent a job from advancing if required measurements are not recorded, and routing enforcement that blocks out-of-sequence operations.