What is poka-yoke?
A short definition of poka-yoke, an example from manual assembly, and how Arkite handles it.
What is poka-yoke?
Poka-yoke is a Japanese term for mistake proofing: designing a process so that an error cannot happen, or is detected immediately at the moment it occurs, before it becomes a defect.
- Prevents errors or detects them at the moment they occur
- Originates from the Toyota Production System
- Physical fixtures or digital checks
Poka-yoke in manual assembly
Classic poka-yoke uses physical means, such as a fixture that only fits one way or a part count tray. In manual assembly with many variants, physical poka-yoke is often hard to apply to every step.
Digital poka-yoke adds checks in software and sensors: the next step only starts when the current one is confirmed as correct, a tool only works at the right position, and a wrong part triggers a warning at once.
Example: a smart screwdriver is enabled only when the operator is at the correct screw position, and the next step waits until the required torque is confirmed.
How Arkite handles it
- Each pick and placement checked by a 3D sensor
- The next step starts only after a correct action
- Smart tools enabled only at the right step and position
- A camera can inspect the product before it moves on
Questions about poka-yoke
What is the difference between poka-yoke and inspection?
Inspection finds defects after they happen. Poka-yoke prevents the error or detects it at the moment it occurs, so no defect is produced.
Does poka-yoke work for high-mix assembly?
Physical poka-yoke is hard to apply to many variants. Digital checks follow the variant on the workbench, so they work for high-mix assembly as well.
Which errors can be prevented?
Typical errors are wrong or missing parts, skipped steps, sequence errors and wrong tool use.
See it on your own product.
A live demo shows how Arkite guides, checks and records manual work.