What I learned during my years working in Georgetown, Kentucky for Toyota was several operating philosophies were developed after WWII. These were opposite the well-developed Mass Production System. I observed “Build In Station” , “Just-In-Time”, “Level Scheduling”, “Cascading Annual Planning”, and most important “Team Participation”.
Each of these principles are unachievable by definition. No company can ever achieve 100% of these principles. This is why all Toyota employees will tell you we will never arrive and we will always use this system to identify waste and engage every Team Member in solving abnormalities and reduce cost while enhancing their individual identity with their positions in the company.
Each of these principles required various lean tools such as; Standardized Work, Andon Communication, Team Leaders, Kanban, Material Deliver Routes, Participation Models of Opportunity etc. We have been chasing these tools individually for the past 40 years with limited success at best.
Remember Lean is the Complex Whole of your system and Lean Tools are the parts.
Good Luck On Your Lean Journey