Lean manufacturing

Lean manufacturing or lean production is a systematic method originating in the Japanese manufacturing industry for the minimization of waste (無駄, muda) within a manufacturing system without sacrificing productivity, which can cause problems. Lean also takes into account waste created through overburden (無理, muri) and unevenness in work loads (斑, mura). Working from the perspective of the client who consumes a product or service, 'value' is any action or process that a customer would be willing to pay for.I was first introduced to the concepts of just-in-time (JIT) and the Toyota production system in 1980. Subsequently I had the opportunity to witness its actual application at Toyota on one of our numerous Japanese study missions. There I met Mr. Taiichi Ohno, the system's creator. When bombarded with questions from our group on what inspired his thinking, he just laughed and said he learned it all from Henry Ford's book.' The scale, rigor and continuous learning aspects of TPS have made it a core concept of lean. Lean manufacturing or lean production is a systematic method originating in the Japanese manufacturing industry for the minimization of waste (無駄, muda) within a manufacturing system without sacrificing productivity, which can cause problems. Lean also takes into account waste created through overburden (無理, muri) and unevenness in work loads (斑, mura). Working from the perspective of the client who consumes a product or service, 'value' is any action or process that a customer would be willing to pay for. Lean manufacturing attempts to make obvious what adds value, through reducing everything else (because it is not adding value). This management philosophy is derived mostly from the Toyota Production System (TPS) and identified as 'lean' only in the 1990s. TPS is renowned for its focus on reduction of the original Toyota seven wastes to improve overall customer value, but there are varying perspectives on how this is best achieved. The steady growth of Toyota, from a small company to the world's largest automaker, has focused attention on how it has achieved this success. Lean principles are derived from the Japanese manufacturing industry. The term was first coined by John Krafcik in his 1988 article, 'Triumph of the Lean Production System', based on his master's thesis at the MIT Sloan School of Management. Krafcik had been a quality engineer in the Toyota-GM NUMMI joint venture in California before joining MIT for MBA studies. Krafcik's research was continued by the International Motor Vehicle Program (IMVP) at MIT, which produced the international best-selling book co-authored by James P. Womack, Daniel Jones, and Daniel Roos called The Machine That Changed the World. A complete historical account of the IMVP and how the term 'lean' was coined is given by Holweg (2007). For many, lean is the set of 'tools' that assist in the identification and steady elimination of waste. As waste is eliminated quality improves while production time and cost are reduced.A non exhaustive list of such tools would include: SMED, value stream mapping, Five S, Kanban (pull systems), poka-yoke (error-proofing), total productive maintenance, elimination of time batching, mixed model processing, rank order clustering, single point scheduling, redesigning working cells, multi-process handling and control charts (for checking mura). There is a second approach to lean manufacturing, which is promoted by Toyota, called The Toyota Way, in which the focus is upon improving the 'flow' or smoothness of work, thereby steadily eliminating mura ('unevenness') through the system and not upon 'waste reduction' per se. Techniques to improve flow include production leveling, 'pull' production (by means of kanban) and the Heijunka box. This is a fundamentally different approach from most improvement methodologies, and requires considerably more persistence than basic application of the tools, which may partially account for its lack of popularity.