tl;dr: Lean is not just about speed or efficiency. Lean, properly understood, improves flow and quality at the same time–along with safety, cost, and morale. The idea that Lean “makes bad stuff faster” is a persistent Lean Six Sigma myth that ignores Toyota’s actual practices and the foundations of the Toyota Production System. Update, 2026: I’ve since written a fuller, sourced version of this argument — the history of the myth, what Toyota actually says, … Continue reading If Someone Teaches You That Lean Is Just About Speed, Walk (or Run) Away