There's an entire book (I've read it) about this called "The Machine That Changed The World" published in the early 90's. It goes into great depth as to the issues that were plaguing GM/Ford etc. The excess inventory was absolutely not driven by too little demand. It was simply inefficiency in the manufacturing process and inability to rapidly reconfigure the shop floor or reallocate labor towards bottlenecks.

The book is a deep, academic examination of the roots of lean production, and is a must read for any engineer who wants to get the Agile cultists to shut up and go away. I'm a hardcore believer in the ACTUAL Agile philosophy, which is rooted in lean, and I despise the cult of clerics that have risen up around it and turned it into management consulting BS. That book helps to know real agile from consultant billing hours agile.

  > I'm a hardcore believer in the ACTUAL Agile philosophy, which is rooted in lean

would then the work of juran, demming, goldratt et al, be good reading as well?

I'm a fan of anything that is rooted in reality and has been battle-tested. If it's theoretical, I don't care about it. Toyota didn't will lean into thin air out of nothing. It was evolved, tested, and refined in the harsh economic realities of post WW2 Japan. Bullshit wasn't capable of surviving that environment, just things that actually worked.

A lot of the Demming types are pure theory, or just garbage in the modern age.

  > A lot of the Demming types are pure theory, or just garbage in the modern age

wasnt alot of demmings writings used by japanese companies in general though?

i guess what your saying is, its better to study those companies themselves, even if influenced by said person...?