QAM - Quality Assurance Management

In the last decade several management tools were introduced and implemented worldwide. (DOE, Lean, Six Sigma, ISO, Lean Sigma, TQM, etc)

Sometimes to make a business model feasible and successful  more than approach has to be implemented which raises the question…..

Which process, tools or management principals have you implemented successfully (or not) and what was the outcome.

Please share your experience !

Thanks in advance