Earlier quoted context omitted.
My pet conspiracy theory is that Toyota's liberal knowledge sharing with competitors is really a psy-op to keep the competitors perpetually on the edge of ruin while they laugh all the way to the bank. They don't even have to be deceptive about it. Just in time is obviously about not having undue spare capacity, not about not having any spare capacity at all. But Toyota knows this nuance is going to be lost on buzzwo…
Toyota knows it competitive edge is its culture. Culture to change, to be retrospective, to improve. Lean, JIT, Kanban etc were derived from a culture of striving for perfection and to develop the optimal processes for a specific company is something that takes decades and is never ending, not something that can be read in a book, taught on a course in a short period of time.
I have no idea of whether this is true at all, but I really like the story anyway.
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What I do know is true is that modern day Toyota doesn't mind sharing the solutions they have come up with to various problems, because they think the real value is in the people and processes to (a) identify the problems in the first place, and (b) come up with solutions suited to those specific problems.
Blindly applying Toyota's solutions to Toyota's problems to your organisation, just hoping that you have the same problems as Toyota and that their solutions will work also for you is a recipe for confusion, and not what matters. (Yet virtually every "development methodology" is a specific solution to a specific problem blindly applied to an organisation.)