Lean Manufacturing is an advanced methodology that focuses on identifying and eliminating the "waste" detected during manufacturing processes.
Lean has its origins in the Toyota Production System (TPS) developed after the Second World War in Japan.
The founder of TPS was Taiichi Ohno. Another important contributor to this system was Shigeo Shingo.
The 3 types of waste in TPS are: Muda, Muri and Mura.
Within "Muda", Toyota TPS identified seven wastes: Defects, Overproduction, Transportation, Waiting, Inventory, Motion and Processing (DOTWIMP).
Lean principles originate from the Toyota Production System. "Lean" term was first used by John Krafcik in a 1988 article: "Triumph of the Lean Production System".
Later, in 1990, James Womack, Daniel Jones and Daniel Roos published a book "The Machine That Changed The World" in which they used the term "Lean Production".
Lean has 5 principles (as defined by the Lean Entreprise Institute in the U.S.): Identify Value, Map the Value Stream, Create Flow, Establish Pull and Seek Perfection.
Lean has a set of tools, many of them derived from the Toyota Production System. Lean had an 8th waste added to the initial 7 Toyota TPS wastes: "Talent" (underutilizing people's talents, skills, knowledge, ideas or suggestions).
The Lean set of tools are implemented gradually in manufacturing organizations. It can take many years for an organization to train employees, have all the tools properly implemented and develop a strong Lean system.
Some Lean tools that are commonly used by world-class manufacturing companies are:
5S, Kaizen, 8 Wastes, Visual Management, Value Stream Mapping, PDCA, A3 Method, Standardized Work, Process Design for Flow, Set-Up Reduction, Built-in-Quality, Total Productive Maintenance, Error-Proofing (Poka-Yoke), Kanban, Material Replenishment, Change Management.