Fameuse phrase du livre The Mythical Man-Month de Fred Brooks, je trouve qu'elle colle très bien à la méthode scientifique de Lean.  

Il commence le chapitre "Plan to Throw One Away", par l'exemple suivant:

Chemical engineers learned long ago hat a process that works in the laboratory cannot be implemented in a factory in only one step.  An intermediate step called the pilot plan is necessary to give experience in scaling quantities up and operating in nonprotective environments.