Fail-Safe Design or POKA YOKE
The zero defect system – or Shingo System – was developed by Shigeo Shingo, the Co-Developer of the Toyota Production System.
It relies on controls consisting of fail-safe devices called POKA YOKE including such things as checklists or special tooling ranging, from kitting parts, from a bin to sophisticated detection and electronic signalling devices.
Of course, prevention is the most effective method for zero defects. Minor prevention devices, like equipment for detecting errors, for stopping the process (Jidoka-Autonomation) and for correcting errors, are therefore also important components of this concept.
Poka Yoke may also include improvements that consist of design changes – changes that need more than machine- or process improvements. They affect the shape of the product itself, like the elimination of unused holes on a printed circuit board to prevent errors while assembling or wiring.