> In particular, one mustn’t stockpile parts on the floor, they must be fed in small quantities at small time intervals.

I'd imagine that is hugely affected by the lead time on the parts in question. If you're in a Japanese industrial town and every part's manufactured within 20km of your factory, it'd be a perfect approach. If you're in Palo Alto, California and some of your parts are manufactured in a Japanese industrial town, then "just enough" stockpiled parts may well be a three month supply.