Mistake Proofing

“To err is human,” but that does not mean customers are willing to accept defective products. Mistake Proofing, or Poka-Yoke, provides methods for increasing the visibility of errors, improving reaction time to errors and creating systems to prevent errors from recurring.

Mistake Proofing is the practice of striving for zero defects using techniques, standards and devices that prevent errors from being made. It also provides for detection of and stopping errors before they become defects by using shutdown, control or warning.

The most effective way of reducing or eliminating defects due to errors is to prevent them at the source. The Mistake Proofing process has three levels of application:

  1. Level one focuses on keeping the defective product from reaching the next operation, or the customer and typically employs inspection sheets, checklists, or costly sort and inspect activities.
  2. Level two is sometimes referred to as the warning level as it provides a notification (Light, Sound, etc.) to the operator that a defect has occurred.
  3. Level three is the highest level of Mistake Proofing and encompasses all controls implemented to prevent the defect from occurring.

The best location for a mistake proofing device is before the operator or the machine starts the task. Prevent the error by not allowing the process to start unless a set of conditions exist. Ideally, mistake-proofing should be considered during the development of a new product to maximize opportunities to mistake-proof through design of the product and the process.

Ask yourself a question: How many times does your customer pay you for a product?

Answer: Once

What happens to your margin if a defect occurs?

If your company has a high level of rework, production stoppages due to defects, or additional costs for containment and inspection, contact your local solutions consultant to start your journey toward attainment of zero defects.