There is a very good video of a speech by John Shook of the Lean Enterprise Institute, titled Lean Change Is Organizational and Personal. Watch it to learn about the California factory that went from the very worst GM plant to the very best GM plant in 1 year, with the same workforce.
Back in the mid-1980s this NUMMI factory became a joint venture between Toyota and GM. The goal for Toyota was to learn how to manage a factory the Toyota way, outside of Japan. The goal of GM was presumably to make their worst plant perform better. The result is an interesting story.
John Shook points out that one of the safe assumptions of Lean thinking is that "everybody is having problems all of the time" therefore hiding problems is one of the worst things we can do. This lesson of exposing and solving problems was alive for many years at NUMMI but sadly it did not spread as quickly to the rest of General Motors, as we can see from the recent news of recalls and the management attitude to hide problems.
In the video John Shook also explains that Lean requires an experimentation mindset rather than an implementation mindset. In his words, the implementation mindset focuses on "getting it right" while the experimentation mindset focuses on "finding the failures" and being more tolerant of mistakes. Perhaps the mindset required is experimentation, but the result required from Lean must be more than discovery of failures. Success with Lean does require bottom-line results, and these come not only from experimentation but from upgrading broken processes when necessary, by implementing proven Lean models, methods and systems.
Another way to explain this idea may be to say that "we experiment through KAIZEN™ to implement a Lean system". The Lean system and its sub-systems will be implemented differently and look different in different contexts. But Lean implementations are recognizably similar. The best Lean implementations are mandated and supported top-down and put in place bottom-up by enabling the people who do the work to redesign and improve their work. KAIZEN™ is a method to achieve, sustain and improve a Lean (or any) system.
I do agree that Lean is both organizational and personal. With KAIZEN™ built-in, Lean must be personal. When people practice KAIZEN™, they learn to observe reality, see the facts and to solve problems. People learn better when experimentation is encouraged, and both success and failure are permitted. That is another reason why hiding problems is a bad thing; it removes opportunities to learn. Management in a Lean system do not blame, isolate people from the facts or hide problems. They develop people who solve problems while striving for higher standards, higher goals.