Poka yoke is a simple, cost-effective device designed to catch or prevent errors at their source, ensuring 100% inspection and feedback to stop defects from reaching the customer. It operates on levels of effectiveness, from detecting defects downstream to preventing them entirely through innovative solutions. Examples of poka yoke include visual aids for inspections, contrast in paint, and automated systems that stop errors before they occur.

2. QUALITY AT SOURCE
Error
Detection Prevention
an error has occurred
warning or attention style
poka yoke
alerts when error has
occurred
an error is about to occur
control or shut down
style poka yoke
prevents the error from
occurring
Poka Yoke

3. Poka Yoke
Simple, inexpensive device designed to catch
or prevent errors at their source.
• Also known as ‘Mistake Proofing’
• Performs 100% inspection
• Provides feedback of errors before they become defects
• They are built into the process…at the source
• A pillar of Zero Quality Control

4. Poka Yoke
Poka Yoke device characteristics
• Based on Simplicity and Ingenuity
• Part of the process, permitting 100% inspection
• Placed at the source, where the error occurs
• Designed to STOP a defect from ever occurring
• Uses Creativity over Capital

5. Poka Yoke Levels
Level A | Good
• Defect exists, but is stopped further downstream
• Added cost, but prevented from being passed on to
the customer

6. Level B | Better
• Defect exists, but detected before the next process
• No further cost added
Poka Yoke Levels

7. Level C | Best
• Prevent defects from occurring
• Prevention poka yoke that is simple and low cost
Poka Yoke Levels

8. Poka Yoke: Example 1
Description:
These washers have a polymer that squirts out when direct
tension reaches a predetermined level. Checking the tension
of bolts becomes a simple visual inspection.

9. Poka Yoke: Example 2
Description:
Ceilings are usually painted white. Repainting a ceiling usually involves putting white
paint on a background of the previous coat of white paint. Glidden has made this task
more mistake proof by inventing pink ceiling paint that dries white. The paint provides
contrast when needed, but dries to the intended color.

10. Poka Yoke: Example 3
Description:
This star-shaped, clear-plastic wheel effectively checks the orientation of the cups that
pass beneath it. If any cups are upside down, the solid bottom prevents the wheel from
turning, bringing the flow of cups to an abrupt halt.

11. Poka Yoke: Example 4
Description:
This airline’s online payment system has code written that will prevent an error from
occurring by not allowing the process to continue without proper information being
provided. This protects the customer and the provider from input mistakes.

12. Poka Yoke: Example 5
Description:
This sign provides instructions on using some unique markings on the road. Large white
dots are spaced on the road so that if a motorist can see two of them they are not
following too close (tail-gating), thus helping to prevent accidents.

13. Poka Yoke: Example 6
Description:
The Broselow tape is shown draped over the blue satchel. Emergency Medical personnel
measure a child with the tape. The color on the tape indicates which packet to use to treat
the child. Everything is appropriately dosed and sized.

14. In Summary
• Poka Yoke detects errors and prevents defects from
reaching the customer
• Poka Yoke is an integral part of zero quality control
• Poka Yoke is a continuous improvement tool that
enhances the operating system
• Poka Yoke paves the road to zero defects