The term lean has become way too overloaded with complex management ideologies and procedural scaffolding. This is one reason I have come to dislike it. Leanness is a variable in a process optimization model, not an ideology. Cutting the fat is not an unqualified good idea and can actually be dangerous. Lean as ideology often turns into anorexia.
But the core idea is a useful one. In any work process, leanness is simply the amount of work in various stages of completion between input and output. Stuff near the input is raw material inventory, stuff near the middle is parts inventory, and stuff near the output is completed inventory. The sum is Work-In-Progress (WIP), loosely speaking.
I suspect lean became an ideology because of the obesity of 1970s industrial processes in America. Now we’ve come to the other end of the pendulum swing. Anorexia is widespread.
How do you manage leanness without ideology?