Abstract

Shigeo Shingo criticizes statistical process control (SPC) and recommends using mistake-proofing (poka-yoke) devices instead for controlling processes. In this article, the authors demonstrate that Shingo's process control techniques - self-checks and successive checks -- are inferior to SPC measurement control charts. The authors also indicate how source inspection, another mistake-proofing technique, can be used in conjunction with SPC to improve quality and manage the variance of process measurements.