Lean manufacturing is a management philosophy, derived from the Toyota Production System, focused on maximizing customer value while eliminating waste. Its five principles are: define value, map the value stream, create flow, establish pull, and pursue perfection.
Lean is built on two pillars — Just-in-Time and jidoka — and a foundation of stability (5S, standard work, leveling). Above all it is a culture of continuous improvement driven by the people doing the work.