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 the whole (the material machinery job product) as an object, the distribution (variation) sees 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 in 1920 age the Walter A shoe heart of the American Bell Telephone Laboratories (Walter A. Shewhart) what devises the utilization of statistical method as the method of making the production quality in mass production 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 which occupied US (GHQ), with radio use you feel 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", Deming (W.Edwards Deming) inviting the doctors, 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 the indian type quality control (TQC) to with eventually.

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