Methods & toolsPoka-yoke / Mistake-Proofing

What is Poka-yoke?

Poka-yoke is Japanese for “mistake-proofing”: a design of process or equipment that makes it physically impossible — or immediately visible — to make an error. Examples: plugs that only fit one way, sensors that stop the machine when a component is missing.

The principle is that people make mistakes, and that it is the process’s responsibility to catch them — not the employee’s responsibility to be flawless. A good poka-yoke is cheap, simple and catches the error at the source, before it becomes a defect.

Poka-yoke ranks above inspection in effectiveness: inspection finds errors after they have occurred; mistake-proofing prevents them from occurring.

Related concepts

Jidoka

Jidoka — often translated “automation with a human touch” — is the principle that processes stop themselves at deviations, so defects are never passed on. Jidoka is the second pillar of the Toyota Production System alongside Just-in-Time.

Quality at the source

Quality at the source is the principle that errors should be detected and stopped where they arise — by the process and the employee that create them — instead of being caught by inspection further down the chain. No defect is passed on.

Standard work

Standard work is the currently best, agreed way of performing a task — documented so precisely that deviations can be seen, and improvements have a fixed starting point. Without a standard there is no deviation; without deviation, no learning.

From concept to practice

The methods only work when they are anchored in daily routines and leadership behaviour. The operations check shows in 4 minutes where your operations stand — and what the next step is.

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