The architect of the Toyota Production System, Taiichi Ohno, described the 5 Whys method as "the basis of Toyota's scientific approach by repeating why five times the nature of the problem as well as its solution becomes clear."
Glavni arhitekt korporacije Toyota Production Systems, Taiichi Ohno opisao je tehniku kao “bazu za Toyotine znanstvene pristupe jer ponavljanjem pitanja “zašto” pet puta, uzroci problema postaju jasniji.”