I really like Bev's drunk driving analogy so I'm going to continue with it. So the TPS implementation is failing because your (I don't mean you specifically, please don't take offense) not doing the root cause analysis, poke yoke, and other quality steps, and then you blame it on TPS. That's like blaiming the perfectly good vehicle for getting stuck on a muddy road even though you didn't try putting it in four wheel drive.
TPS/lean/demingism (whatever you want to call it) works. It's a perfectly good vehicle to bettering the capabilities of your factory. It's all about making the vehicle run in your environment.
Since I am not doing the implementation I don't take it personally.
The point I'm trying to make is the vehicle was not perfectly good (out of alignment, missing a wheel and headed off a cliff) but the results of a flawed quality system.
Without a solid design process based on compliance to a quality system we attempted lean. Implementing lean over a flawed system only allows for you to make more bad product faster or in lean terms gives you a greater chance to pull the chain and stop the process.
The question should be which comes first the chicken or the egg. I believe without a structured quality system based on prevention, lean will as my previous company did fail.
Lean is reactive and not preventive. Many have stated that you must fail to implement new corrective actions why not plan ahead using FEMA's, Control Plans, etc. Then again if your company was not failing you might not be implementing lean in the first place.