“Those who are not dissatisfied will never make any progress “Those who are not dissatisfied will never make any progress.” - Shingo (1909 – 1990)

Dr. Shigeo Shingo Industrial engineer Born January 8, 1909 in Saga City, Japan In 1955 he took charge of industrial engineering and factory improvement training at the Toyota Motor Company He was a leading proponent of statistical process control in the 1950s, but became frustrated with the statistical approach as he realized that it would never reduce product defects to zero Died November 14, 1990 at the age of 81

Zero Quality Control (ZQC) An approach to quality management that relies heavily on the use of Poka Yoke devices Successive checks Self-checks Each method relies on 100% inspection whereas traditional SPC rely on random checks

Poka Yoke Japanese for mistake-proofing Poka - inadvertent mistake Yoke – prevent Developed in the 1960s Either prevents a mistake from being made or makes the mistake obvious at a glance

“The cause of defects lie in worker errors, and defects are a result of neglecting those errors – mistakes will not turn into defects if worker errors are discovered and eliminated beforehand” - Shingo What would Dr. Deming have to say about that?

Three types of inspection Judgment inspection Informative inspection Source inspection Often Poka Yoke devices ensure the proper operating conditions exist prior to actual production

PokaYoke Device Categories Prevention device - make errors impossible Detection device - Make errors visible to the operator  

Characteristics of Good Poka Yoke Devices they are simple and cheap they are part of the process they are placed close to where the mistakes occur John Grout’s Poka Yoke Site