
The Birth of Lean ◾ 13
meant smaller batches and quick die
17
changeovers. Ohno’s workers invented
quick die changeover. Where a changeover could take a day or longer at a
typical mass producer, Toyota’s workers could do it in a matter of minutes.
Remarkably, Ohno found that producing smaller batches with quick
changeovers actually resulted in cost savings. Small batches also improved
quality because defects could be detected more quickly and reduced lead
times because there was less work-in-process. Many of his subsequent dis-
coveries also proved to be counterintuitive.
At Toyota I came to understand that our problems today are those Toyota ...