Lean manufacturing

Lean manufacturing is a management system built on three principles: produce only what is needed, when it is needed; correct abnormalities as soon as they occur; and empower workers to improve the process themselves.

At its core, Lean eliminates activities that do not add value for the customer. Where just-in-time (JIT) manufacturing focuses on inventory strategy — receiving goods only as needed to reduce costs and waste — Lean goes further by reducing cycle time, flow time, and throughput time across the entire system, including marketing and customer service. According to one study: "While Just-In-Time manufacturing focuses on efficiency of inventory strategy to eliminate waste and enhance productivity, Lean manufacturing uses efficiency in its system setups to reduce cycle, flow, and throughput times being the added values to customers."

By receiving goods only when needed, Lean reduces inventory costs and wastage, while increasing productivity and profit. A successful operation depends on producers having fast and high-quality processes that can generate on-demand, result of involving workers bottom-up.

Origins

Early foundations

Frederick Winslow Taylor documented manufacturing efficiencies in Principles of Scientific Management (1911), and Henry Ford applied these ideas in the early 1900s. However, these methods addressed physical organization only, not management systems or culture.

Before World War II, American statistician W. Edwards Deming and Walter A. Shewhart developed the earliest formalized modern manufacturing philosophies, applying statistical models to improve efficiency in large U.S. military manufacturers during the war. American industry largely rejected their methods at the time.

Continuous production improvement and incentives for such were documented in Taylor's Principles of Scientific Management (1911):

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