Jeff Sutherland in his book "The Art of doing twice the work in half the time" describes how he created the Scrum master and Product Owner roles. "My inspiration for the role came from Toyota's Chief Engineer. A Chief Engineer is responsible for a whole product line, such as Corolla or Camry. To do this, they have to draw on talents of groups specializing in Body engineering, chassis, electrical etc.... The Chief engineer has to draw from all those groups a cross-functiinal team capable of creating a car... but he simply can't say something has to be done... he has to persuade, cajole, and demonstrate that his way is the right way,the best way. it usually takes someone with 30 yrs experience to fulfill this role. I wanted that in Scrum, but I'm well aware that very few people have that high level of skill and expertise. So I split the role in two, giving the Scrum master the How and Product owner the What."
