Poka Yoke

Poka Yoke (pronounced "poh-kah yoh-kay") translates into English as to avoid (yokeru) iinadvertent errors (poka). Mistake Proofing is a bunch of small devices that are used to either detect or prevent defects from occurring in the first place. Poka Yoke is commonly used to reduce defects/rework or to tighten the improvement solutions.

Types of mistake proofing

  • Elimination: Redesign the system to eliminate the chance of the error (Control method)
  • Facilitation: Provide methods of guidance, hard and soft, to minimise the chance of an error
  • Mitigation: Lessen the effect of the error if the resulting defect gets to the customer
  • Flagging: Proven methods for insuring 100% chance of capturing and removing all defective units prior to shipment (Warning method)


  1. Describe the defect and its impact on customers
  2. Identify the process step where the defect is discovered and the step where it is created
  3. Detail the standard procedures where the defect is created
  4. Identify errors in or deviation from the standard procedure
  5. Investigate and analyze the root cause for each deviation
  6. Brainstorm ideas to eliminate or detect the deviation early
  7. Create, test, validate, and implement mistake-proofing device