Developed by Shigeo Shingo (Zero Quality Control: Source Inspection and the Poka-yoke System, English edition, 1986).
Designs physical or procedural constraints so an error cannot be made, or is caught the moment it happens, before it becomes a defect.
When to reach for it
When the same human error keeps causing defects and more inspection or more reminders have not stopped it.
How it runs
- List the recurring errors in the process.
- For each, ask whether a constraint can prevent it.
- If not, add a check that catches it at once or stops the line.
- Build the constraint into the process.
- Confirm it works without creating new errors.
Where it sits in SOLVE eX
Go to the source
- Zero Quality Control: Source Inspection and the Poka-yoke System, Productivity Press, English edition, 1986