Shewhart se agbekale awọn iṣakoso chart ni 1924 ati awọn Erongba ti a ipinle ti iṣiro iṣakoso. iṣiro iṣakoso jẹ dogba si awọn Erongba ti exchangeability ni idagbasoke nipa logician William Ernest Johnson tun ni 1924 ninu rẹ iwe Logic, Part III: The Logical Foundations of Science. Paapọ pẹlu kan egbe ni AT & T ti o ni Harold Dodge ati Harry Romig o ṣiṣẹ lati fi ayẹwo ayẹwo lori a rational iṣiro ipilẹ bi daradara. Shewhart ti ni imọran pẹlu Colonel Leslie E. Simon ni awọn ohun elo ti iṣakoso awọn aworan si ohun ija manufacture ni Army ká Picatinny Arsenal ni 1934.
Àwọn Ilé Iṣẹ́ Bell