In method of quality control, those which are used making use of statistical technique. It is not one one quality of the product, it measures quality characteristic production process whole (material machinery job product) as an object, looks at the distribution (variation) and manages. When it is set, as conformity/the nonconformity quality characteristic for standard it is expressed in non-defective item ratio/proportion defective.

20 century beginnings, the product quality due to industrial production depended on the skill and inspection of the skill by the worker, but what devises the utilization of statistical method as the method of making the production quality the Walter A shoe heart (Walter A. Shewhart) of the American Bell Telephone Laboratories in mass production in 1920 age fixed, makes beginning. That really, under troop guidance, in case of the World War II until it is adapted in the US military demand industry it was not executed.

After the war, the US military (GHQ) which occupied US with radio use feels concern about the fact that communication it is heard in the Soviet Union, determining that the technique of SQC where in order to improve, also military secret could say the quality of the indian wire communication below is transplanted to the indian communication equipment manufacturer. On the one hand, "defeat of the" US military physical quantity maneuvers "as technology", inviting Doctors Deming (W.Edwards Deming), it tackles cause of defeat the quality control which is based on statistical technique positively even in the indian industry which has been considered, these activities develop to the indian typequality control(TQC) eventually.

Furthermore, there was a ride in advance example that separately from the flow of this shoe heart, in US the Ishida preservation loyal retainer of Tokyo electricity (present Toshiba), introduces technique of cirque Pearson (Karl Pearson) into light bulb production in 1920 age.