“The key to success is to have a production system that highlights problems and a human system that produces people who are able and willing to identify and solve them. This requires team-minded people who are not only competent enough and well trained enough to identify and solve a problem, but who also trust their supervising group leader, feel safe in identifying the problem, and are motivated to solve it.” 

Toyota Culture  by Jeffrey Liker & Michael Hoseus (McGraw Hill, 2008) p. 39.