If you were to ask me “What is the single most important Lean tool or method,” my answer would immediately be “genba kaizen” – with the understanding that no employee loses their job as a result of kaizen; i.e. “Respect for People” is operational in this and in many other ways.
Why? It is because classic industrial engineering-based kaizen is how you:
Genba kaizen is fundamental. It also:
Process improvement tools and methods used in isolation do not have the same impact that genba kaizen has. And, only genba kaizen can re-wire your brain from the current state (batch-and-queue way of thinking) to the future state (flow way of thinking).
The great majority of authors of influential Lean books never got their hands dirty on the shop floor. They do not understand genba kaizen or its significance, and therefore paid little attention to it in their writings and speeches. As a result, many Lean practitioners today think they are doing kaizen when, in fact, they are not. And, they are certainly not achieving the individual development, organizational capability-building, and business results that comes with classic industrial engineering-based kaizen genba kaizen.
The one method that leaders of the Lean community should have emphasized the most, genba kaizen, is what they emphasized the least. The result is widespread Fake Lean and failed Lean transformations.
However, it is not too late to re-connect with genba kaizen and make the kind of progress that you had hoped to make.