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