Lean
Origin
The Toyota Production System was developed by Taiichi Ohno throughout the 1950s and 1960s in response to Toyota's need to produce efficiently with scarce resources in post-war Japan. Ohno identified the seven types of waste (muda) that do not add value: overproduction, waiting, transportation, overprocessing, inventory, motion, and defects.
The term "Lean" (lean manufacturing) was coined by James Womack, Daniel Jones, and Daniel Roos in their influential book The Machine That Changed the World (1990), after studying the Toyota system and comparing it with Western mass production.
The 14 Lean principles
The principles drawn from the Toyota system form the philosophical foundation of Lean:
- Business decisions are based on a long-term vision, even at the expense of short-term financial losses.
- Production cycles are short and fast.
- "Pull" systems, which prevent overproduction, are preferred.
- The workload must be leveled (Heijunka).
- Lean culture includes stopping production to solve problems and teaching their methodical study (Jidoka).
- Tasks are standardized to achieve continuous improvement (Kaizen).
- Simple visual management reveals problems and enables coordination.
- Only proven technology that is useful to people and the process is used.
- Leaders are developed who understand the work, live the philosophy, and pass it on.
- Exceptional teams and people who follow the organization's philosophy are developed.
- The network of partners and suppliers (Keiretsu) is respected and helped to improve.
- Managers go to the workplace (Genchi Genbutsu) to understand situations firsthand.
- Decisions are made by consensus, considering all options, followed by rapid implementation.
- The company learns through constant reflection (Hansei) and continuous improvement (Kaizen).
Some common practices in Lean environments
- Kanban: visual display of production-related information, kept permanently up to date in the workplace.
- 5S: a workplace organization methodology whose name comes from five Japanese words: seiri, seiton, seiso, seiketsu, shitsuke (sort, set in order, shine, standardize, and sustain).
- Pokayoke: mistake-proofing systems that only allow the work to be done the right way.
- JIT (Just in Time): producing only when and in the quantity required.
- Andon: visual alert systems that signal anomalies and problems at the time and place of production.
- Jidoka: building systems into the process that check quality and stop the line when they detect a defect.
- Heijunka: techniques for leveling production and adapting it to fluctuating customer demand.
Lean and agility
Agile project management frameworks—Scrum, Kanban, Lean Software Development—are applications of Lean principles to software development and knowledge management. They share an emphasis on eliminating waste (unnecessary documentation, bureaucratic processes, waiting between phases), continuous delivery of value, and continuous improvement through cycles of retrospection and adaptation.
Common mistake
Reducing Lean to a list of tools. 5S, kanban, and Pokayoke are specific practices, but Lean is above all a management philosophy: respect for people, an obsession with customer value, and a commitment to continuous improvement. Without that philosophical foundation, Lean tools become efficiency initiatives that are applied superficially and do not produce lasting change.
References
- Liker, Jeffrey K. (2004). The Toyota Way: 14 Management Principles from the World's Greatest Manufacturer. McGraw-Hill.
- Womack, James; Jones, Daniel; Roos, Daniel. (1990). The Machine That Changed the World. Simon & Schuster.
See also
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