SPC bụ nke Walter A. Shewhart malitere na Bell Laboratories na mbido 1920s. Shewhart mepụtara eserese njikwa na 1924 na echiche nke steeti njikwa ọnụ ọgụgụ. Nchịkwa ọnụ ọgụgụ kwekọrọ n'echiche nke mgbanwe nke onye na-eche echiche bụ William Ernest Johnson mepụtara na 1924 n'akwụkwọ ya Logic, Nkebi nke III: Ntọala Ntọala nke Sayensị. Ya na otu ndị otu na AT&T gụnyere Harold Dodge na Harry Romig ọ rụrụ ọrụ iji tinye nlele nlele na ndabere ọnụ ọgụgụ ezi uche dị na ya.
Ụlọ nyocha Bell