Making an operational lean is a journey of many years, not a big-bang endeavor. Still, we discovered that the lean approach is already having a significant impact. The lean projects we studied performed no better than others on measures of quality, perhaps because standards were already high. 

But they produced superior results in terms of time and cost. On average, the lean projects were completed in 5% less time than had been anticipated; the other projects typically finished at the forecasted time. And the lean projects came in 9% under budget; the others were 2% under budget.