To say, however, that lean is not uniquely Japanese doesn’t mean that there is nothing Japanese about it. So, let’s explore this second, little explored, idea. […] by asking more questions. One critical question we can ask ourselves is: “Could have TPS emerged anywhere other than Japan?” And finally, “What, if anything, is Japanese about lean thinking?”

My attempt to address these questions – an ever-changing effort as I reflect more and the world around us keeps evolving – has taken the shape of the graph you see below, which illustrates what I call the “Toyota double funnels”. There are three main sections to the graphic:

• The left funnel represents a selection of key ingredients that, combined, have led to the creation of Toyota’s way of working.
• The spiral in the middle of the graphic represents the actual genesis of the Toyota Way, TPS, TPD, TMS and lean thinking, which can be traced back to a 30-year period of incubation, between 1950 and 1980.
• The right funnel represents the diffusion of this body of knowledge around the world, which started around the time of the NUMMI experiment, in 1984.

[…]I believe the spread of lean has been both a matter of diffusion and of dilution.[…] Along with the dilution, there’s been more than a little delusion, aided by consultants selling things under the name of “lean” that are far from the original intent of the thinking, system, and application.”

John Shook’s double funnel is reproduced here. Click on it to enlarge or view it on Planet Lean to click on each item and see more details.