More and more often, companies that follow a lean implementation path realize that the results deriving just from the application of the most basic tools often guarantee temporary results that are only satisfactory in the short term. An aspect that is often overlooked, but essential for the effective achievement of a lean structure, consists in the training of operators and, more generally, of all actors in a given company. The aim of this paper is to understand how different training methods, such as the instructor-led classroom training, on-the-job training, vestibule training, and coaching lead to different learning results in the context of a lean implementation. The results are contextualized within the process mapping phase, specifically in the adoption of Value Stream Mapping at three different companies, for each of which a different training program was designed.