View source for Lean manufacturing

{{short description|Methodology used to improve production}}
{{use American English|date=March 2024}}{{use mdy dates|date=March 2024}}
{{for|the drug|Lean (drug)#Preparation}}

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|heading1 = [[Three-sector model]]
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* [[Primary sector]] ''([[raw material]]s)''
* [[Secondary sector]] ''([[goods]] [[manufacturing]])''
* [[Tertiary sector]] ''([[Service (economics)|services]])''

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* [[Quaternary sector of the economy|Quaternary sector]] (information services)
* [[Quinary sector of the economy|Quinary sector]] (human services)

|heading3 = Developers
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* [[William Edwards Deming|Dr. William Edwards Deming]], [[Walter A. Shewhart]], [[Shigeo Shingo]], [[Taiichi Ohno]], [[Henry Ford]], [[Frederick Winslow Taylor|Frederick Taylor]] 
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* [[Business sector]]
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'''Lean manufacturing'''  is an American invented [[methods of production|method]] of [[manufacturing]] goods aimed primarily at improving efficiency within the [[Operations management#Production systems|production system]] as well as response times from suppliers and [[customer]]s. Its earliest applications can be traced back to German manufacturing principles, first implemented during the [[Industrial Revolution]] in agricultural production and small factories. However, the term "Lean" was not used to describe these and other manufacturing efficiency methods and philosophies until the 1980s. 

Before WWII, [[William Edwards Deming|Dr. William Edwards Deming]] began to formalize the first true "Lean" philosophy for modern manufacturing while working for the US [[Bureau of Statistics]].<ref>{{cite web |last1=Roser |first1=Christoph |title=25 Years after W. Edwards Deming |url=https://www.allaboutlean.com/25-years-deming/ |website=allaboutlean.com |publisher=AALean GmbH |access-date=11 October 2025}}</ref> Later, Deming invented the first "Lean" manufacturing method and management philosophy, known as '''[[Total Quality Management]]''', which continues to be used as the foundational teachings of Lean today.<ref>{{cite web |last1=Pollins |first1=Martin |title=Deming and the Total Quality Management (TQM) Revolution |url=https://martinpollins.com/2024/04/15/deming-and-the-total-quality-management-tqm-revolution/ |website=martinpollins.com |publisher=Martin Pollins, CA and MBA |access-date=11 October 2025}}</ref> From there, the '''Just-in-time manufacturing''' (JIT manufacturing) process grew, first in Japan and then around the world. Just-in-time manufacturing tries to match production to [[Supply and demand|demand]] by only supplying [[goods]] that have been ordered and focuses on efficiency, [[productivity]] (with a commitment to [[continuous improvement]]), and reduction of "wastes" for the producer and supplier of goods. Lean manufacturing adopts the just-in-time approach and additionally focuses on reducing [[Cycle time variation|cycle]], flow, and [[Throughput (business)|throughput]] times by further eliminating activities that do not add any [[Value (economics)|value]] for the customer.<ref>According to {{Citation |title=Intelligent Manufacturing and Mechatronics: Proceedings of SympoSIMM 2021 |editor1=Mohd Najib Ali Mokhtar |editor2=Zamberi Jamaludin |editor3=Mohd Sanusi Abdul Aziz |editor4=Mohd Nazmin Maslan |editor5=Jeeferie Abd Razak |chapter=Lean Manufacturing Design of a Two-Sided Assembly Line Balancing Problem Work Cell |author1=Kamarudin Abu Bakar |author2=Mohd Fazli Mohd. Sam |author3=M.I. Qureshi |publisher=Springer Nature |date=2022 |page=250}}: "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."</ref> Lean manufacturing also involves people who work outside of the manufacturing process, such as in [[marketing]] and customer service.

Lean manufacturing (also known as agile manufacturing) is particularly related to the operational model implemented in the [[post-war]] 1950s and 1960s by the Japanese automobile company [[Toyota]] called the [[Toyota Production System]] (TPS), known in the United States as "[[The Toyota Way]]".<ref>{{cite book|last1=Ohno|first1=Taiichi|title=Toyota Production System: Beyond Large-Scale Production|date=1988|publisher=CRC Press|isbn=978-0-915299-14-0}}</ref><ref name="Shingo">Shingo, Shigeo. 1985. ''A Revolution in Manufacturing: The SMED System''. Stamford, Ct.: Productivity Press</ref> Toyota's system was erected on the two pillars of just-in-time inventory management and automated quality control. 

The seven "wastes" ({{Transliteration|ja|[[Muda (Japanese term)|muda]]}} in Japanese), first formulated by Toyota engineer Shigeo Shingo, are:
# the waste of superfluous [[inventory]] of [[raw material]] and finished goods 
# the waste of overproduction (producing more than what is needed now) 
# the waste of over-processing (processing or making parts beyond the standard expected by customer), 
# the waste of transportation (unnecessary movement of people and goods inside the system)
# the waste of excess motion (mechanizing or automating before improving the method) 
# the waste of waiting (inactive working periods due to job queues) 
# and the waste of making defective products (reworking to fix avoidable defects in products and processes).<ref>{{Citation |title=A Dictionary of Business and Management |editor=Jonathan Law |date=2009 |publisher=Oxford University Press}}</ref>

The term ''Lean'' was coined in 1988 by American businessman [[John Krafcik]] in his article "Triumph of the Lean Production System," and defined in 1996 by American researchers [[James P. Womack|Jim Womack]] and [[Daniel T. Jones (author)|Dan Jones]] to consist of five key principles: "Precisely specify value by specific product, identify the value stream for each product, make value flow without interruptions, let customer pull value from the producer, and pursue perfection."<ref>{{citation |last1=Womack |first1=James P. |last2=Jones |first2=Daniel T. |title=Lean Thinking: Banish Waste And Create Wealth In Your Corporation |date=2003 |publisher=Simon and Schuster |isbn=9781471111006 |url=https://books.google.com/books?id=QZrZAAAAQBAJ&pg=PP1 |page=10 |access-date=October 2, 2020 |archive-date=October 22, 2021 |archive-url=https://web.archive.org/web/20211022143733/https://books.google.com/books?id=QZrZAAAAQBAJ&pg=PP1 |url-status=live }}</ref>

Companies employ the strategy to increase efficiency. By receiving goods only as they need them for the production process, it reduces inventory costs and wastage, and increases productivity and profit. The downside is that it requires producers to forecast demand accurately as the benefits can be nullified by minor delays in the supply chain. It may also impact negatively on workers due to added stress and inflexible conditions. A successful operation depends on a company having regular outputs, high-quality processes, and reliable suppliers.

== History ==
[[Frederick Winslow Taylor|Frederick Taylor]] documented many observations relating to manufacturing efficiencies and [[Henry Ford]] applied Taylor's and early German manufacturing principles at the Ford manufacturing plant in the early 1900s. However, these methods were limited to physical organizational efficiencies and not the management philosophies and statistical methods Lean also requires. [[Toyota]]'s [[Shigeo Shingo]] and [[Taiichi Ohno]] were first introduced to Lean's formalized manufacturing efficiency methods and philosophies after WWII by the father of "Lean Manufacturing", [[William Edwards Deming|Dr. William Edwards Deming]]. Deming's Total Quality Management (TQM) lectures in Japan were widely celebrated and rapidly incorporated into Japanese manufacturing during the Reconstruction period.

In 1988 manufacturing efficiencies and philosophies were dubbed ''Lean'' by [[John Krafcik]], and then were defined in ''[[The Machine That Changed the World (book)|The Machine that Changed the World]]''<ref>{{citation |last1=Womack |first1=James P. |last2=Jones |first2=Daniel T. |last3=Roos |first3=Daniel |title=Machine that Changed the World |date=1990 |publisher=Rawson Associates |location=New York |isbn=9780892563500 |url=https://books.google.com/books?id=_n5qRfaNv9AC&pg=PR4 |access-date=October 2, 2020 |archive-date=February 19, 2022 |archive-url=https://web.archive.org/web/20220219163438/https://books.google.com/books?id=_n5qRfaNv9AC&pg=PR4 |url-status=live |pages=13–15}}</ref> and further detailed by [[James P. Womack|James Womack]] and [[Daniel T. Jones (author)|Daniel Jones]] in ''Lean Thinking'' (1996).

=== Japan: the origins of Lean ===
[[Image:W. Edwards Deming.jpg|thumb|W. Edwards Deming]]The adoption of just-in-time manufacturing in Japan and many other early forms of Lean can be traced back directly to the US-backed Reconstruction and [[Occupation of Japan]] following WWII. In the years preceding this, an American economist, [[W. Edwards Deming]], and an American statistician, [[Walter A. Shewhart]], promoted the earliest formalized modern manufacturing methods and management philosophies that they developed in the late '30s and early '40s.<ref>{{cite web |title=Deming the Man |url=https://www.youtube.com/watch?v=tDu47czfwiI&t=15s |website=youtube | date=March 2, 2013 |publisher=Deming Institute |access-date=27 October 2024}}</ref> The two experts were the first to apply these newly developed statistical models to improve efficiencies in many of America's largest military manufacturers during WWII. However, Deming and Shewhart failed to convince other US manufacturers to apply these "radical" methods during this period and the following three decades. 

After the war, Deming was assigned to participate in the Reconstruction of Japan by General [[Douglas MacArthur]]. Deming participated as a manufacturing consultant for Japan's struggling heavy industries, which included [[Toyota]] and [[Mitsubishi]]. Unlike what they experienced in the US, Deming found the Japanese very receptive to learning and applying these new efficiency methods. Many of the manufacturing methods first introduced by Deming in Japan, and later innovated by Japanese companies, are what we now call Lean Manufacturing. Japanese manufacturers still recognize Deming for his contributions to modern Japanese efficiency practices by awarding the best manufacturers in the world the [[Deming Prize]].<ref>{{cite web |last1=Deming Philosophy and Principles |title=Deming Philosophy and Principles &#124; Columbia Business School |url=https://business.columbia.edu/demingcenter/about/deming-philosophy-and-principles |website=columbia.edu |publisher=Columbia University |access-date=27 October 2024}}</ref><ref>{{cite web |last1=Hunter |first1=John |title=Toyota's Management History |url=https://deming.org/toyotas-management-history/ |website=deming.org |publisher=Deming Institute |access-date=27 October 2024}}</ref><ref>{{cite web |title=W. Edwards Deming American statistician and educator |url=https://www.britannica.com/biography/W-Edwards-Deming |website=britannica.com |date=October 10, 2024 |publisher=Britannica |access-date=27 October 2024}}</ref><ref>{{cite web |title=The Legacy of W. Edwards Deming |url=https://asq.org/quality-progress/articles/the-legacy-of-w-edwards-deming?id=bdbc9d974ad7471db42609ccabcd76d9 |website=asq.org |publisher=American Society of Quality |access-date=27 October 2024}}</ref> In addition to Deming's critical influence in Japan, most local companies were in a position where they needed an immediate solution to the extreme situation they were living in after World War II. American supply chain specialist Gerhard Plenert has offered four quite vague reasons, paraphrased here. During Japan's post–World War II rebuilding (of economy, infrastructure, industry, political, and social-emotional stability): 
#Japan's lack of cash made it difficult for industry to finance the big-batch, large inventory production methods common elsewhere.
#Japan lacked space to build big factories loaded with inventory.
#The Japanese islands lack natural resources with which to build products. 
#Japan had high unemployment, which meant that labor efficiency methods were not an obvious pathway to industrial success.

Thus, the Japanese "leaned out" their processes. "They built smaller factories ... in which the only materials housed in the factory were those on which work was currently being done. In this way, inventory levels were kept low, investment in in-process inventories was at a minimum, and the investment in purchased natural resources was quickly turned around so that additional materials were purchased." Plenert goes on to explain Toyota's key role in developing this lean or just-in-time production methodology.<ref>Plenert, G. (2007), ''Reinventing Lean: Introducing Lean Management into the Supply Chain''. Oxford, U.K.: Butterworth-Heinemann. pp. 41–42.</ref>

American industrialists recognized the threat of cheap offshore labor to American workers during the 1910s and explicitly stated the goal of what is now called lean manufacturing as a countermeasure. Henry Towne, past president of the [[American Society of Mechanical Engineers]], wrote in the foreword to Frederick Winslow Taylor's ''Shop Management'' (1911), "We are justly proud of the high wage rates which prevail throughout our country, and jealous of any interference with them by the products of the cheaper labor of other countries. To maintain this condition, to strengthen our control of home markets, and, above all, to broaden our opportunities in foreign markets where we must compete with the products of other industrial nations, we should welcome and encourage every influence tending to increase the efficiency of our productive processes."<ref>{{cite book |last=Levinson |first=William A. |title=Lean Management System LMS:2012: A Framework for Continual Lean Improvement |date=2016 |publisher=CRC Press |isbn=9781466505384 |page=11 |url=https://books.google.com/books?id=8v0GCvH8LR4C&q=%22We%20are%20justly%20proud%20of%20the%20high%20wage%20rates%22&pg=PA11 |access-date=May 5, 2019 |archive-date=August 20, 2021 |archive-url=https://web.archive.org/web/20210820071237/https://books.google.com/books?id=8v0GCvH8LR4C&q=%22We%20are%20justly%20proud%20of%20the%20high%20wage%20rates%22&pg=PA11 |url-status=live }}</ref>

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

* "... whenever a workman proposes an improvement, it should be the policy of the management to make a careful analysis of the new method, and if necessary conduct a series of experiments to determine accurately the relative merit of the new suggestion and of the old standard. And whenever the new method is found to be markedly superior to the old, it should be adopted as the standard for the whole establishment."
* "...after a workman has had the price per piece of the work he is doing lowered two or three times as a result of his having worked harder and increased his output, he is likely entirely to lose sight of his employer's side of the case and become imbued with a grim determination to have no more cuts if soldiering [marking time, just doing what he is told] can prevent it."

[[Shigeo Shingo]] cites reading ''Principles of Scientific Management'' in 1931 and being "greatly impressed to make the study and practice of scientific management his life's work".<ref>{{cite book |last1=Shingo |first1=Shigeo |translator-last=Dillon |translator-first=Andrew P. |title=The Sayings of Shigeo Shingo: Key Strategies for Plant Improvement |date=1987 |publisher=Productivity Press |location=New York |isbn=0-915299-15-1 |url=https://books.google.com/books?id=e0laDwAAQBAJ&q=The%20Sayings%20of%20Shigeo%20Shingo%3A%20Key%20Strategies%20for%20Plant%20Improvement&pg=PT18 |access-date=October 2, 2020 |archive-date=February 19, 2022 |archive-url=https://web.archive.org/web/20220219163409/https://books.google.com/books?id=e0laDwAAQBAJ&q=The+Sayings+of+Shigeo+Shingo%3A+Key+Strategies+for+Plant+Improvement&pg=PT18 |url-status=live }}</ref>{{Request quotation |date=October 2019}}<sup>, </sup><ref>{{cite book |last1=Shingo |first1=Shigeo |title=A Revolution In Manufacturing: The SMED System |date=1985 |publisher=Productivity Press |location=Portland, Oregon |isbn=0-915299-03-8 |url=https://books.google.com/books?id=ooXVVIfqEQwC&pg=PA6 |access-date=October 2, 2020 |archive-date=August 20, 2021 |archive-url=https://web.archive.org/web/20210820093656/https://books.google.com/books?id=ooXVVIfqEQwC&pg=PA6 |url-status=live }}</ref>{{Page needed|date=October 2019}}

Basing their methods on Deming's teachings, Shingo and [[Taiichi Ohno]] led the redesign of Toyota's manufacturing process after WWII. Previously a textile company, [[Toyota]] had moved into building automobiles in 1934. [[Kiichiro Toyoda]], the founder of Toyota Motor Corporation, directed the engine casting work and discovered many problems in their manufacturing, with wasted resources on the repair of poor-quality castings. Toyota engaged in intense study of each stage of the process. In 1936, when Toyota won its first truck contract with the Japanese government, the processes encountered new problems, to which Toyota responded by developing [[Kaizen]] improvement teams, which later became the [[Toyota Production System]] (TPS), and subsequently [[The Toyota Way]].

Levels of demand in the postwar economy of Japan were low; as a result, the focus of mass production on lowest cost per item via economies of scale had little application. Having visited and seen supermarkets in the United States, Ohno recognized that the scheduling of work should not be driven by sales or production targets but by actual sales. Given the financial situation during this period, over-production had to be avoided, and thus the notion of "pull" (or "build-to-order" rather than target-driven "push") came to underpin production scheduling.

=== Evolution in the rest of the world ===
Although some ideas of lean manufacturing were practiced on a small scale in the 1950s by the British Motor Corporation (Australia),<ref>{{Cite web |url=https://portal.engineersaustralia.org.au/system/files/engineering-heritage-australia/nomination-title/BMC_Plant_Nomination.pdf |title=Archived copy |access-date=June 1, 2021 |archive-date=September 4, 2021 |archive-url=https://web.archive.org/web/20210904201027/https://portal.engineersaustralia.org.au/system/files/engineering-heritage-australia/nomination-title/BMC_Plant_Nomination.pdf |url-status=live }}</ref> and concepts of lean material flow can be traced back to Henry Ford’s My Life and Work (1922), where he argued that raw materials should ideally arrive directly into production without stockpiling,<ref>{{Cite web |url=https://www.tribuneschoolchd.com/uploads/tms/files/1595165525-samuel-crowther-and-henry-ford.pdf |title=My Life and Work |access-date=August 21, 2025 }}</ref> the Just-in-Time philosophy was popularized and systematized by Toyota as part of the [[Toyota Production System]]. News about just-in-time/Toyota production system reached other western countries from Japan in 1977 in two English-language articles: one referred to the methodology as the "Ohno system", after [[Taiichi Ohno]], who was instrumental in its development within Toyota.<ref>Ashburn, A., 1977. Toyota's "famous Ohno system", ''American Machinist'', July, 120–123.</ref> The other article, by Toyota authors in an international journal, provided additional details.<ref>{{cite journal|last1=Sugimori|first1=Y.|last2=Kusunoki|first2=K.|last3=Cho|first3=F.|last4=Uchikawa|first4=S.|title=Toyota Production System and Kanban System: Materialization of Just-in-time and Respect-for-human System|journal= International Journal of Production Research|date=1977|volume=15|issue=6|pages=553–564|doi=10.1080/00207547708943149|issn=0020-7543|doi-access=free}}</ref> Finally, those and other publicity were translated into implementations, beginning in 1980 and then quickly multiplying throughout industry in the United States and other developed countries. A seminal 1980 event was a conference in Detroit at Ford World Headquarters co-sponsored by the Repetitive Manufacturing Group (RMG), which had been founded 1979 within the American Production and Inventory Control Society (APICS) to seek advances in manufacturing. The principal speaker, Fujio Cho (later, president of Toyota Motor Corp.), in explaining the Toyota system, stirred up the audience, and led to the RMG's shifting gears from things like automation to just-in-time/Toyota production system.<ref>{{cite journal |title=The Founding of the Association for Manufacturing Excellence: Summarized at a Meeting of its Founders, February 2, 2001 |journal=Target |date=2001 |volume=17 |issue=3 |pages=23–24 |url=https://www.ame.org/sites/default/files/target_articles/01-17-3-Founding_AME.pdf |publisher=Association for Manufacturing Excellence |quote=1980: At Bendix in Southfield, MI, the mood darkened. John Kinsey, Ken Wantuck, Doc, Larry and others at this meeting had been exposed to "Japanese manufacturing.” While we dinked with MRP, the Japanese were eating our lunch; something more significant was needed. Afterward, Mac and Nick visited the APICS president to seek recognition as a special interest group of APICS. We became the Repetitive Manufacturing Group (RMG) of APICS, but to front the next workshop, we opened our own bank account. By APICS rules, we weren't supposed to do that. [...] In October, the Detroit APICS Chapter supported by several members of the Repetitive Manufacturing Group sponsored the first-known conference in the United States on "Japanese Manufacturing” at Ford World Headquarters Auditorium. The featured speaker was Fujio Cho, now president of Toyota. |access-date=June 1, 2021 |archive-date=March 9, 2021 |archive-url=https://web.archive.org/web/20210309053843/https://www.ame.org/sites/default/files/target_articles/01-17-3-Founding_AME.pdf |url-status=live }}</ref>

At least some of audience's stirring had to do with a perceived clash between the new just-in-time regime and [[manufacturing resource planning]] (MRP II), a computer software-based system of manufacturing planning and control which had become prominent in industry in the 1960s and 1970s. Debates in professional meetings on just-in-time vs. MRP II were followed by published articles, one of them titled, "The Rise and Fall of Just-in-Time".<ref>Landvater, Darryl. 1984. "The rise and fall of just-in-time". ''Infosystems''. November, p 62.</ref> Less confrontational was Walt Goddard's, "Kanban Versus MRP II—Which Is Best for You?" in 1982.<ref>Goddard, W. 1982. "Kanban versus MRP II—which is best for you?" ''Modern Materials Handling''. November 5, 1982, p 40-48.</ref> Four years later, Goddard had answered his own question with a book advocating just-in-time.<ref name="Goddard 1986"/> Among the best known of MRP II's advocates was George Plossl, who authored two articles questioning just-in-time's kanban planning method<ref>Plossl, G.W. 1981. Japanese productivity: myth vs. reality. ''P&IM Review and APICS News'', September, pp 59–62.</ref> and the "japanning of America".<ref>Plossl, G.W. 1984. The redirection of U.S. manufacturing. ''P&IM Review and APICS News''. November, pp 50–53.</ref> But, as with Goddard, Plossl later wrote that "JIT is a concept whose time has come".<ref>Plossl. G.W. 1986. "J.I.T.&nbsp;– fad or fact of life?" ''P&IM Review and APICS News'', February 1986, p. 24.</ref>

Just-in-time/TPS implementations may be found in many case-study articles from the 1980s and beyond. An article in a 1984 issue of ''Inc''. magazine<ref>Walters, C.R. 1984. Why everybody's talking about "just-in-time." Inc. (March 1) 77–90.</ref> relates how [[Omark Industries]] (chain saws, ammunition, log loaders, etc.) emerged as an extensive just-in-time implementer under its US home-grown name ZIPS, or "zero inventory production system". At Omark's mother plant in [[Portland, Oregon]], after the work force had received 40 hours of ZIPS training, they were "turned loose" and things began to happen. A first step was to "arbitrarily eliminate a week's lead time [after which] things ran smoother. 'People asked that we try taking another week's worth out.' After that, ZIPS spread throughout the plant's operations 'like an amoeba.'" The article also notes that Omark's 20 other plants were similarly engaged in ZIPS, beginning with pilot projects. For example, at one of Omark's smaller plants making drill bits in [[Mesabi|Mesabi, Minnesota]], "large-size drill inventory was cut by 92%, productivity increased by 30%, scrap and rework ... dropped 20%, and lead time ... from order to finished product was slashed from three weeks to three days." The ''Inc''. article states that companies using just-in-time the most extensively include "the Big Four, [[Hewlett-Packard]], Motorola, [[Westinghouse Electric]], [[General Electric]], [[John Deere|Deere & Company]], and [[Black and Decker]]".{{citation needed|date=October 2019}}

By 1986, a case-study book on just-in-time in the U.S.<ref name=Sepehri>Sepehri, Mehran. 1986. ''Just-in-Time: Not Just in Japan: Case Studies of American Pioneers in JIT Implementation''. Falls Church, Va.: American Production and Inventory Control Society</ref> was able to devote a full chapter to ZIPS at Omark, along with two chapters on just-in-time at several Hewlett-Packard plants, and single chapters for [[Harley-Davidson]], John Deere, IBM-Raleigh, North Carolina, and California-based [[Apple Inc.]], a Toyota truck-bed plant, and the [[NUMMI | New United Motor Manufacturing (NUMMI)]] joint venture between Toyota and [[General Motors]].{{citation needed|date=July 2022}}

Two similar, contemporaneous books from the UK are more international in scope.<ref name="Mortimer">{{cite book |last=Mortimer |first=J. |date=1986 |title=Just-in-Time: An Executive Briefing |location=Kempston, Bedford, UK |publisher=IFS Ltd. }}</ref> One of the books, with both conceptual articles and case studies, includes three sections on just-in-time practices: in Japan (e.g., at Toyota, Mazda, and Tokagawa Electric); in Europe (jmg Bostrom, Lucas Electric, Cummins Engine, IBM, 3M, Datasolve Ltd., Renault, Massey Ferguson); and in the US and Australia (Repco Manufacturing-Australia, Xerox Computer, and two on Hewlett-Packard). The second book, reporting on what was billed as the First International Conference on just-in-time manufacturing,<ref name="Ingersoll">Ingersoll Engineers. 1986. ''Just in Time Manufacturing: Proceedings of the First International Conference''. London, UK. April 8–9, 1986.</ref> includes case studies in three companies: Repco-Australia, IBM-UK, and 3M-UK. In addition, a day two keynote address discussed just-in-time as applied "across all disciplines, ... from accounting and systems to design and production".<ref name="Ingersoll"/>{{rp|J1–J9}}

Writing in an east African context, Kigwana notes that terminology also used for similar versions of just-in-time includes "material-as-needed" (MAN) and a system known as "daily overhead and perfect supply in the nick of time" (DOPs).<ref>Kigwana, S., [https://web.archive.org/web/20041022214057/http://www.procnews.com/040531/procnews1.html Any idea of inventory control techniques?], ''East African Procurement News'', published on 24 May 2004, archived on 22 October 2004, accessed on 27 March 2025</ref>

=== Rebranding as "lean" ===
[[John Krafcik]] coined the term ''Lean'' in his 1988 article, "Triumph of the Lean Production System".<ref>{{Cite web |url=https://www.lean.org/downloads/MITSloan.pdf |title=Archived copy |access-date=February 10, 2020 |archive-date=February 12, 2020 |archive-url=https://web.archive.org/web/20200212110809/https://www.lean.org/downloads/MITSloan.pdf |url-status=live }}</ref> The article states: (a) Lean manufacturing plants have higher levels of productivity/quality than non-Lean and (b) "The level of plant technology seems to have little effect on operating performance" (page 51). According to the article, risks with implementing Lean can be reduced by: "developing a well-trained, flexible workforce, product designs that are easy to build with high quality, and a supportive, high-performance supplier network" (page 51).

=== Middle era and to the present ===

Three more books which include just-in-time implementations were published in 1993,<ref>Schniederjans, M.J. 1993. ''Topics in Just-in-Time Management''. Needham Heights, Mass.: Allyn & Bacon</ref> 1995,<ref name=Jasinowski>Jasinowski, Jerry, and Robert Hamrin. 1995. ''Making It in America: Proven Paths to Success from 50 Top Companies''. New York: Simon & Schuster.</ref> and 1996,<ref>Kinni, T.B. 1996. ''America's Best Plants: Industry Week's Guide to World-Class Manufacturing Plants''. New York: Wiley</ref> which are start-up years of the lean manufacturing/lean management movement that was launched in 1990 with publication of the book, ''The Machine That Changed the World''.<ref name="Womack_Jones_Roos">Womack, James P., Jones, Daniel T., and Roos, Daniel. 1990. ''The Machine That Changed the World: The Story of Lean Production''. New York: Rawson Associates.</ref> That one, along with other books, articles, and case studies on lean, were supplanting just-in-time terminology in the 1990s and beyond. The same period, saw the rise of books and articles with similar concepts and methodologies but with alternative names, including ''cycle time management'',<ref name=Thomas>Thomas, P.R. 1991. ''Getting Competitive: Middle Managers and the Cycle Time Ethic''. New York: McGraw-Hill.</ref> ''time-based competition'',<ref name=Blackburn>Blackburn, Joseph T. 1991. ''Time-based Competition: The Next Battleground in American Manufacturing''. Homewood, Ill.; Business One Irwin, p 28.</ref> ''quick-response manufacturing'',<ref>Suri, R. 1998. Quick Response Manufacturing: A Companywide Approach to Reducing Lead Times. Portland, Ore.: Productivity Inc.</ref> flow,<ref>Hirano, Hiroyuki. and Makota Furuya. 2006. JIT Is Flow: ''Practice and Principles of Lean Manufacturing''. Vancouver, Wash.: PCS Press,</ref> and ''pull-based production systems''.<ref>Pettersen, Jan-Arne. 2010. "Pull Based Production Systems: Performance, Modeling and Analysis," doctoral thesis. Lulea, Sweden: Lulea University of Technology.</ref>

There is more to just-in-time than its usual manufacturing-centered explication. Inasmuch as manufacturing ends with order-fulfillment to distributors, retailers, and end users, and also includes remanufacturing, repair, and warranty claims, just-in-time's concepts and methods have application downstream from manufacturing itself. A 1993 book on "world-class distribution logistics" discusses kanban links from factories onward,<ref>Harmon, R.L. 1993. ''Reinventing the Warehouse: World Class Distribution Logistics.'' New York: Free Press</ref> and a manufacturer-to-retailer model developed in the U.S. in the 1980s, referred to as ''quick response'',<ref>Lowson, B., R. King, and A. Hunter. 1999. Quick Response&nbsp;– Managing the Supply Chain to Meet Consumer Demand. Chichester, UK: Wiley.</ref> has morphed over time to what is called ''[[fast fashion]]''.<ref>Hines, T. 2001. "From analogue to digital supply chains: Implications for fashion marketing, " in ''Fashion Marketing: Contemporary Issues''. eds, T. Hines and M. Bruce. Oxford: Butterworth Heinemann, 26–47.</ref><ref>Hines, T. 2004. Supply Chain Strategies: Customer Driven and Customer Focused. Oxford, UK: Elsevier.</ref>

== Methodology ==
The strategic elements of lean can be quite complex, and comprise multiple elements. Four different notions of lean have been identified:<ref name="Pettersen">Pettersen, J., 2009. Defining lean production: some conceptual and practical issues. The TQM Journal, 21(2), 127 - 142.</ref>

# Lean as a fixed state or goal (being lean)
# Lean as a continuous change process (becoming lean)
# Lean as a set of tools or methods (doing lean/toolbox lean)
# Lean as a philosophy (lean thinking)

The other way to avoid market risk and control the supply efficiently is to cut down in stock. P&G has completed their goal to co-operate with Walmart and other wholesales companies by building the response system of stocks directly to the suppliers companies.<ref>{{cite web|title=Shining examples|url=https://www.economist.com/special-report/2006/06/17/shining-examples|publisher=The Economist|location=Special report: Logistics|date=June 15, 2006|access-date=June 13, 2017|archive-date=February 20, 2018|archive-url=https://web.archive.org/web/20180220040311/http://www.economist.com/node/7032179|url-status=live}}</ref>

In 1999, Spear and Bowen<ref>{{cite journal | first2 = H. Kent | last2 = Bowen | first1 = Steven | last1 = Spear | date = September 1999 | title = Decoding the DNA of the Toyota Production System | journal = Harvard Business Review | url = http://hbr.org/1999/09/decoding-the-dna-of-the-toyota-production-system/ar/1 | access-date = February 20, 2013 | archive-date = March 7, 2016 | archive-url = https://web.archive.org/web/20160307014648/https://hbr.org/1999/09/decoding-the-dna-of-the-toyota-production-system/ar/1 | url-status = live }}</ref> identified four rules which characterize the "Toyota DNA":

# All work shall be highly specified as to content, sequence, timing, and outcome.
# Every customer-supplier connection must be direct, and there must be an unambiguous yes or no way to send requests and receive responses.
# The pathway for every product and service must be simple and direct.
# Any improvement must be made in accordance with the [[scientific method]], under the guidance of a teacher, at the lowest possible level in the organization.

This is a fundamentally different approach from most improvement methodologies, and requires more persistence than basic application of the tools, which may partially account for its lack of popularity.<ref>Liker, Jeffrey K. and Michael Hoseus (2008) Toyota Culture: The Heart and Soul of The Toyota Way, McGraw-Hill, New York p. 3-5 {{ISBN|978-0-07-149217-1}}</ref> The implementation of "smooth flow" exposes quality problems that already existed, and waste reduction then happens as a natural consequence, a system-wide perspective rather focusing directly upon the wasteful practices themselves.

Takt time is the rate at which products need to be produced to meet customer demand. The JIT system is designed to produce products at the rate of takt time, which ensures that products are produced just in time to meet customer demand.<ref>{{Cite web |last=Jaiswal |first=Vishal |title=Just-in-Time (JIT): Principle, Components, Revolution, Advantages, & Disadvantages |url=https://www.mechanicalsite.com/2023/05/just-in-time-jit.html |archive-url=https://web.archive.org/web/20230506140735/https://www.mechanicalsite.com/2023/05/just-in-time-jit.html |url-status=usurped |archive-date=May 6, 2023 |access-date=May 6, 2023 }}</ref>

Sepheri provides a list of methodologies of just-in-time manufacturing that "are important but not exhaustive":<ref>Sepheri, M., p. 277.{{full citation needed|date=March 2016}}</ref>

* Housekeeping: physical organization and discipline.
* Make it right the first time: elimination of defects.
* Setup reduction: flexible changeover approaches.
* Lot sizes of one: the ultimate lot size and flexibility.
* Uniform plant load: leveling as a control mechanism.
* Balanced flow: organizing flow scheduling throughput.
* Skill diversification: multi-functional workers.
* Control by visibility: communication media for activity.
* Preventive maintenance: flawless running, no defects.
* Fitness for use: producibility, design for process.
* Compact plant layout: product-oriented design.
* Streamlining movements: smoothing materials handling.
* Supplier networks: extensions of the factory.
* Worker involvement: small group improvement activities.
* Cellular manufacturing: production methods for flow.
* Pull system: signal [kanban] replenishment/resupply systems.

=== Key principles ===

Womack and Jones define Lean as "...a way to do more and more with less and less—less human effort, less equipment, less time, and less space—while coming closer and closer to providing customers exactly what they want" and then translate this into five key principles:<ref>James P Womack, Daniel T Jones, ''Lean Thinking'', 2nd Edition, {{ISBN|978-0-7432-4927-0}}, March 1, 2003)
</ref>

# Value: Specify the value desired by the customer. "Form a team for each product to stick with that product during its entire production cycle", "Enter into a dialogue with the customer" (e.g. [[Voice of the customer]])
# The Value Stream: Identify the [[Value-stream mapping|value stream]] for each product providing that value and challenge all of the wasted steps (generally nine out of ten) currently necessary to provide it
# Flow: Make the product flow continuously through the remaining value-added steps
# Pull: Introduce pull between all steps where continuous flow is possible
# Perfection: Manage toward perfection so that the number of steps and the amount of time and information needed to serve the customer continually falls

Lean is founded on the concept of continuous and incremental improvements on product and process while eliminating redundant activities. "The value of adding activities are simply only those things the customer is willing to pay for, everything else is waste, and should be eliminated, simplified, reduced, or integrated".<ref>D. Rizzardo, R. Brooks, ''Understanding Lean Manufacturing'', Maryland Technology Enterprise Institute, 2003</ref>

On principle 2, waste, see seven basic waste types under [[The Toyota Way]]. Additional waste types are:

* Faulty goods (manufacturing of goods or services that do not meet customer demand or specifications, Womack et al., 2003. See [[Lean services]])
* Waste of skills ([[Six Sigma]])
* Under-utilizing capabilities (Six Sigma)
* Delegating tasks with inadequate training (Six Sigma)
* Metrics (working to the wrong metrics or no metrics) (Mika Geoffrey, 1999)
* Participation (not utilizing workers by not allowing them to contribute ideas and suggestions and be part of Participative Management) (Mika Geoffrey, 1999)
* Computers (improper use of computers: not having the proper software, training on use and time spent surfing, playing games or just wasting time) (Mika Geoffrey, 1999)<ref>{{cite book | title = The Lean Toolbox | last1 = Bicheno |first1= John |last2 = Holweg | first2 = Matthias | publisher= PICSIE |date=2009 |isbn=978-0-9541244-5-8 }}</ref>

'''<span class="anchor" id="Lean 3P">Lean 3P</span>''' is a lean manufacturing approach used in [[new product development]] representing 3 Ps: production, preparation, and process.<ref>{{cite book |last1=Coletta |first1=Allan R. |title=The Lean 3P Advantage: A Practitioner's Guide to the Production Preparation Process |date=15 November 2017 |publisher=CRC Press |isbn=978-1-4398-7912-2 |url=https://www.google.com/books/edition/The_Lean_3P_Advantage/z3HnDwAAQBAJ?hl=en&gbpv=1&dq=try+storming&pg=PA42&printsec=frontcover |language=en}}</ref><ref>{{cite book |last1=MODI |first1=AMSHED A. |title=ESSENTIALS OF OPERATIONS MANAGEMENT |date=1 May 2017 |publisher=PHI Learning Pvt. Ltd. |isbn=978-81-203-5305-3 |pages=251 |url=https://www.google.com/books/edition/ESSENTIALS_OF_OPERATIONS_MANAGEMENT/f__gDgAAQBAJ?hl=en&gbpv=1&dq=lean+3P&pg=PA251&printsec=frontcover |access-date=20 July 2025 |language=ar}}</ref><ref>{{cite book |last1=Shook |first1=John |last2=Marchwinski |first2=Chet |title=Lean Lexicon: A Graphical Glossary for Lean Thinkers |date=21 January 2014 |publisher=Lean Enterprise Institute |isbn=978-1-934109-46-5 |url=https://www.google.com/books/edition/Lean_Lexicon/U8GkAgAAQBAJ?hl=en&gbpv=1&bsq=%203P |language=en}}</ref>

=== Implementation ===
One paper suggests that an organization implementing Lean needs its own Lean plan as developed by the "Lean Leadership". This should enable Lean teams to provide suggestions for their managers who then makes the actual decisions about what to implement. Coaching is recommended when an organization starts off with Lean to impart knowledge and skills to shop-floor staff. Improvement metrics are required for informed decision-making.<ref>{{cite journal |last1=Dombrowski |first1=U. |last2=Mielke |first2=T |title= Lean Leadership&nbsp;– 15 Rules for a Sustainable Lean Implementation |journal= Procedia CIRP |volume=17 |pages=565–570 |doi=10.1016/j.procir.2014.01.146 |date=2014|doi-access=free }}</ref>

Lean philosophy and culture is as important as tools and methodologies. Management should not decide on solutions without understanding the true problem by consulting shop floor personnel.<ref name="Hopp_Spearman">{{Citation |last1=Hopp |first1=Wallace |last2=Spearman |first2=Mark |date=2008 |title=Factory Physics: Foundations of Manufacturing Management |publisher=McGraw-Hill Companies, Incorporated |edition=3rd |isbn=978-0-07-282403-2 |url=http://www.factoryphysics.com/ |postscript=. |access-date=January 5, 2014 |archive-date=May 20, 2019 |archive-url=https://web.archive.org/web/20190520211234/http://factoryphysics.com/ |url-status=live }}</ref>

The solution to a specific problem for a specific company may not have generalized application. The solution must fit the problem.<ref>{{cite web |last=Pederson |first=Joseph |title=Author |url= http://thebusinessdudeblog.com/2014/04/23/fancy-lean-terms-are-not-always-your-solution/ |work=the business dude |publisher=WordPress.com |access-date=April 27, 2014 |url-status=dead |archive-url= https://archive.today/20140427062032/http://thebusinessdudeblog.com/2014/04/23/fancy-lean-terms-are-not-always-your-solution/ |archive-date= April 27, 2014 }}</ref>

[[Value-stream mapping]] (VSM) and [[5S (methodology)|5S]] are the most common approaches companies take on their first steps to Lean. Lean can be focused on specific processes, or cover the entire supply chain. Front-line workers should be involved in VSM activities. Implementing a series of small improvements incrementally along the supply chain can bring forth enhanced productivity.<ref>{{Cite news |url=http://www.inboundlogistics.com/cms/article/the-lean-supply-chain-watch-your-waste-line/ |title=The Lean Supply Chain: Watch Your Waste Line |publisher=inboundlogistics |author=Merrill Douglas |date=June 2013 |access-date=February 22, 2017 |archive-date=March 27, 2019 |archive-url=https://web.archive.org/web/20190327084116/https://www.inboundlogistics.com/cms/article/the-lean-supply-chain-watch-your-waste-line/ |url-status=live }}</ref>

== Naming ==
Alternative terms for JIT manufacturing have been used. [[Motorola]]'s choice was short-cycle manufacturing (SCM).<ref>Heard, Ed. 1987. Short cycle manufacturing: the route to JIT. ''Target''. 2 (3) (fall) 22–24.</ref><ref>High, W. 1987. Short cycle manufacturing (SCM) implementation: an approach taken at Motorola. ''Target'', 3 (4) (Winter), 19–24.</ref> [[IBM]]'s was continuous-flow manufacturing (CFM),<ref>Barkman, William E. 1989. ''In-Process Quality Control for Manufacturing''. Boca Raton, Fl.: CRC Press.</ref><ref>Bowers, G.H., Jr. 1991. Continuous flow manufacturing. ''Proc. SPIE1496, 10th Annual Symposium on Microlithography''. (March 1, 1991), 239–246.</ref> and demand-flow manufacturing (DFM), a term handed down from consultant John Constanza at his Institute of Technology in Colorado.<ref>Roebuck, Kevin. 2011. ''Business Process Modeling: High-impact Emerging Technology&nbsp;— What You Need to Know: Definitions, Adoptions, Impact, Benefits, Maturity, Vendors''. Tebbo, p 32.</ref> Still another alternative was mentioned by Goddard, who said that "Toyota Production System is often mistakenly referred to as the 'Kanban System'", and pointed out that [[kanban]] is but one element of TPS, as well as JIT production.<ref name="Goddard 1986">Goddard, Walter E. 1986. ''Just-in-Time: Surviving by Breaking Tradition''. Essex Junction, Vt." Oliver Wight Ltd.</ref>{{rp|11}}

The wide use of the term ''JIT manufacturing'' throughout the 1980s faded fast in the 1990s, as the new term ''lean manufacturing'' became established<ref>{{cite book|last1=Womack|first1=James P.|last2=Jones|first2=Daniel T.|last3=Roos|first3=Daniel|title=The Machine That Changed the World: The Story of Lean Production|date=2007|publisher=Simon and Schuster|isbn=9781416554523|url=https://books.google.com/books?id=9NHmNCmDUUoC&pg=PP1|access-date=May 24, 2017|archive-date=June 2, 2021|archive-url=https://web.archive.org/web/20210602234403/https://books.google.com/books?id=9NHmNCmDUUoC&pg=PP1|url-status=live}}</ref>{{page needed|date=May 2017}}<sup>, </sup><ref>{{cite book|last1=Black|first1=J. Temple|last2=Hunter|first2=Steve, L.|title=Lean Manufacturing Systems and Cell Design|date=2003|publisher=Society of Manufacturing Engineers|isbn=9780872636477|page=41|url=https://books.google.com/books?id=VuPTsESCTXMC&pg=PA307|access-date=June 1, 2021|archive-date=June 2, 2021|archive-url=https://web.archive.org/web/20210602231525/https://books.google.com/books?id=VuPTsESCTXMC&pg=PA307|url-status=live}}</ref>{{Request quotation|date=November 2017}} as "a more recent name for JIT".<ref>{{cite book|last1=Hyer|first1=Nancy|last2=Wemmerlov|first2=Urban|title=Reorganizing the Factory: Competing Through Cellular Manufacturing|date=2001|publisher=CRC Press|isbn=9781563272288|page=41|url=https://books.google.com/books?id=qfJgCYGRJHgC&pg=PA41|quote=Lean manufacturing is a more recent name for JIT. As with JIT, lean manufacturing is deeply rooted in the automotive industry and focuses mostly on repetitive manufacturing situations."|access-date=June 1, 2021|archive-date=June 2, 2021|archive-url=https://web.archive.org/web/20210602233647/https://books.google.com/books?id=qfJgCYGRJHgC&pg=PA41|url-status=live}}</ref> As just one testament to the commonality of the two terms, ''Toyota production system (TPS)'' has been and is widely used as a synonym for both JIT and lean manufacturing.<ref>Monden, Yasuhiro, ed. 1986. ''Applying Just in Time: The American/Japanese Experience''. Norcross, Ga.: Institute of Industrial Engineers. This collection of JIT articles includes multiple references to TPS.</ref>{{Request quotation|date=May 2017}}<sup>, </sup><ref>Womack, J.P. and D. Jones. 2003. ''Lean Thinking: Banish Waste and Create Wealth in Your Corporation''. Revised. New York: Free Press. Numerous references to both lean and TPS.</ref>

== Objectives and benefits ==

Objectives and benefits of JIT manufacturing may be stated in two primary ways: first, in specific and quantitative terms, via published case studies; second, general listings and discussion.

A case-study summary from Daman Products in 1999 lists the following benefits: reduced cycle times 97%, setup times 50%, lead times from 4 to 8 weeks to 5 to 10 days, flow distance 90%. This was achieved via four focused (cellular) factories, pull scheduling, kanban, visual management, and employee empowerment.<ref>Grahovec, D. and Bernie Ducan, Jerry Stevenson, Colin Noone. 1999. How lean focused factories enabled Daman to regain responsiveness and become more agile. ''Target''. 4th quarter, pp 47–51.</ref>

Another study from NCR (Dundee, Scotland) in 1998, a producer of make-to-order automated teller machines, includes some of the same benefits while also focusing on JIT purchasing: In switching to JIT over a weekend in 1998, eliminated buffer inventories, reducing inventory from 47 days to 5 days, flow time from 15 days to 2 days, with 60% of purchased parts arriving JIT and 77% going dock to line, and suppliers reduced from 480 to 165.<ref>Caulkin, Simon. 1990. Britain's best factories. ''Management Today''. November 60–89.</ref>

Hewlett-Packard, one of western industry's earliest JIT implementers, provides a set of four case studies from four H-P divisions during the mid-1980s.<ref>Simpson, Alex. Effective just-in-time manufacture at Hewlett-Packard. In {{harvp|Mortimer|1986|pp=123–128}}.</ref> The four divisions, Greeley, Fort Collins, Computer Systems, and Vancouver, employed some but not all of the same measures. At the time about half of H-P's 52 divisions had adopted JIT.

{| class="wikitable"
|-
!
! Greeley
! Fort Collins
! Computer Systems
! Vancouver
|-
| Inventory reduction
| 2.8 months
| 75%
| 75%
| 
|-
| Labor cost reduction
| 30%
| 15%
| 
| 50%
|-
| Space reduction
| 50%
| 30%
| 33%
| 40%
|-
| WIP stock reduction
| 22 days to 1 day
| 
| 
| 
|-
| Production increase
| 100%
| 
| 
| 
|-
| Quality improvement
| 
| 30% scrap, 79% rework
| 80% scrap
| 30% scrap & rework
|-
| Throughout time reduction
| 
| 50%
| 17 days to 30 hours
| 
|-
| Standard hours reduction
| 50%
| 
| 
| 
|-
| No. of shipments increase
| 
| 
| 
| 20%
|}

==Application outside a manufacturing context==
{{also|Lean services|Lean dynamics|Lean higher education|Lean product development|Lean Six Sigma|Lean software development|Lean thinking|Lean CFP driven}}
Lean principles have been successfully applied to various sectors and services, such as call centers and healthcare. In the former, lean's waste reduction practices have been used to reduce handle time, within and between agent variation, accent barriers, as well as attain near perfect process adherence.<ref>{{cite web |last1=Adsit |first1=Dennis |title=Cutting-Edge Methods Help Target Real Call Center Waste |url=http://www.isixsigma.com/library/content/c070611a.asp |publisher=iSixSigma.com |archive-url=https://web.archive.org/web/20080414194658/http://www.isixsigma.com/library/content/c070611a.asp |archive-date=April 14, 2008 |date=June 11, 2007}}</ref>{{Request quotation|date=November 2017}} In the latter, several hospitals have adopted the idea of ''lean hospital'', a concept that prioritizes the patient, thus increasing the employee commitment and motivation, as well as boosting medical quality and cost effectiveness.<ref>{{cite web |last1=Koch|first1=Arno|title=Makigami in hospital: Lumbosacral radicular syndrome |url=https://www.makigami.info/makigami/where-to-use/makigami-in-hospital/ |website=Makigami Info |date=May 24, 2016 |access-date=7 May 2025}}</ref><ref>{{cite book|last1=Alkalay|first1=M.|last2=Angerer|first2=A.|last3=Drews|first3=T.|last4=Jäggi|first4=C.|last5=Kämpfer|first5=M.|last6=Lenherr|first6=I.|last7=Valentin|first7=J.|last8=Vetterli|first8=C.|last9=Walker|first9=D.|editor1-last=Walker|editor1-first=Daniel|title=The Better Hospital: Excellence Through Leadership And Innovation|date=2015|publisher=Medizinisch Wissenschaftliche verlagsgesellschaft|isbn=9783954662241}}</ref>{{Request quotation|date=November 2017}}

Lean principles also have applications to software development and maintenance as well as other sectors of information technology (IT).<ref>Hanna, Julia, [http://hbswk.hbs.edu/item/5741.html "Bringing ‘Lean' Principles to Service Industries"] {{Webarchive|url=https://web.archive.org/web/20150801115015/http://hbswk.hbs.edu/item/5741.html |date=August 1, 2015 }}, ''HBS Working Knowledge''. October 22, 2007. (Summary article based on published research of Professor David Upton of Harvard Business School and doctoral student Bradley Staats: Staats, Bradley R., and David M. Upton. "Lean Principles, Learning, and Software Production: Evidence from Indian Software Services", ''Harvard Business School Working Paper'', No. 08-001. July 2007, revised July 2008, March 2009)</ref> More generally, the use of lean in information technology has become known as [[Lean IT]].{{citation needed|date=June 2017}} Lean methods are also applicable to the public sector, but most results have been achieved using a much more restricted range of techniques than lean provides.<ref>{{cite book|last1=Radnor|first1=Zoe|last2=Walley|first2=Paul|last3=Stephens|first3=Andrew|last4=Bucci|first4=Giovanni|title=Evaluation of the Lean Approach to Business Management and ITs Use in the Public Sector|date=2006|publisher=Scottish Executive Social Research|isbn=0755960564|url=http://www.gov.scot/Resource/Doc/129627/0030899.pdf|access-date=June 13, 2017|archive-date=January 28, 2018|archive-url=https://web.archive.org/web/20180128221757/http://www.gov.scot/Resource/Doc/129627/0030899.pdf|url-status=live}}</ref>{{Page needed|date=June 2017}}

The challenge in moving lean to services is the lack of widely available reference implementations to allow people to see how directly applying lean manufacturing tools and practices can work and the impact it does have. This makes it more difficult to build the level of belief seen as necessary for strong implementation. However, some research does relate widely recognized examples of success in retail and even airlines to the underlying principles of lean.<ref name="ruffa">{{cite book |last=Ruffa |first=Stephen A. |title=Going Lean: How the Best Companies Apply Lean Manufacturing Principles to Shatter Uncertainty, Drive Innovation, and Maximize Profits |date=2008 |url=https://books.google.com/books?id=_Q7OGDd61hkC |publisher=AMACOM |isbn=978-0-8144-1057-8 |access-date=September 24, 2016 |archive-date=March 2, 2017 |archive-url=https://web.archive.org/web/20170302041151/https://books.google.com/books?id=_Q7OGDd61hkC |url-status=live }}</ref> Despite this, it remains the case that the direct manufacturing examples of 'techniques' or 'tools' need to be better 'translated' into a service context to support the more prominent approaches of implementation, which has not yet received the level of work or publicity that would give starting points for implementors. The upshot of this is that each implementation often 'feels its way' along as must the early [[industrial engineering]] practices of Toyota. This places huge importance upon sponsorship to encourage and protect these experimental developments.{{citation needed|date=June 2017}}

Lean management is nowadays implemented also in non-manufacturing processes and administrative processes. In non-manufacturing processes is still huge potential for optimization and efficiency increase.<ref>JANUŠKA, M., ŠŤASTNÁ, L. Industrial Engineering in the Non-Manufacturing Processes. In Proceedings of the 22nd International Business Information Management Association Conference. neuveden: International Business Information Management Association (IBIMA), 2013. s. 747-766. {{ISBN|978-0-9860419-1-4}}</ref> Some people have advocated using STEM resources to teach children Lean thinking instead of computer science.<ref>{{cite web | url=https://www.nj.com/opinion/2022/02/we-need-to-teach-our-kids-to-think-lean-opinion.html | title=We need to teach our kids to think Lean &#124; Opinion | date=February 3, 2022 }}</ref>

Lean manufacturing methodology has become a prevalent practice in public healthcare, commonly known as lean healthcare.<ref>{{cite journal |last1=Winkel |first1=Jörgen |last2=Edwards |first2=Kasper |last3=Birgisdóttir |first3=Birna Dröfn |last4=Gunnarsdóttir |first4=Sigrún |title=Facilitating and inhibiting factors in change processes based on the lean tool 'value stream mapping':an exploratory case study at hospital wards |journal=International Journal of Human Factors and Ergonomics |date=November 13, 2015 |volume=3 |issue=3–4 |pages=291–302 |doi=10.1504/IJHFE.2015.073000|url=https://backend.orbit.dtu.dk/ws/files/127256364/authorFinalVersion.pdf }}</ref> Due to the intensively competitive environment, lean approach becomes a growing alternative in the healthcare sector to achieve optimized resource management and performance improvement.<ref>{{cite journal |last1=Senna |first1=Pedro |last2=Gomes |first2=Andreia |last3=Monteiro |first3=Aluisio |last4=Pinha |first4=Denis |title=Facilitating and inhibiting factors in change processes based on the lean tool 'value stream mapping': An exploratory case study at hospital wards |journal=Brazilian Journal of Operations & Production Management |date=2016-12-30 |volume=13 |issue=4 |pages=406–420 |doi=10.1504/IJHFE.2015.073000|url=https://backend.orbit.dtu.dk/ws/files/127256364/authorFinalVersion.pdf }}</ref>

== Criticism ==
According to Williams, it becomes necessary to find suppliers that are close by or can supply materials quickly with limited advance notice. When ordering small quantities of materials, suppliers' minimum order policies may pose a problem, though.<ref>{{cite web|last=Williams|first=John T.|title=Pros & Cons of the JIT Inventory System|date=October 6, 2010 |url=http://smallbusiness.chron.com/pros-cons-jit-inventory-system-3195.html|publisher=Houston Chronicle|quote=Supply-chain relationships require retooling that involves multiple suppliers, closer locations, or companies that can supply materials with little advance notice. Companies ordering smaller amounts of goods may encounter difficulty meeting minimum orders, requiring a different contract or a way to break up a large order over time or among several smaller manufacturers.|access-date=June 1, 2021|archive-date=June 3, 2021|archive-url=https://web.archive.org/web/20210603131945/https://smallbusiness.chron.com/pros-cons-jit-inventory-system-3195.html|url-status=live}}</ref>

Employees are at risk of [[precarious work]] when employed by factories that utilize just-in-time and flexible production techniques. A longitudinal study of US workers since 1970 indicates employers seeking to easily adjust their&nbsp;workforce in response to supply and demand&nbsp;conditions respond by creating more nonstandard work arrangements, such as contracting and temporary work.<ref>{{Cite journal |last=L. |first=Kalleberg, A.|title=Precarious Work, Insecure Workers: Employment Relations in Transition |url=https://www.academia.edu/2673815 |journal=American Sociological Review |volume=74 |issue=1 |pages=1–22 |issn=0003-1224 |doi=10.1177/000312240907400101 |date=2009 |citeseerx=10.1.1.1030.231 |s2cid=29915373 |access-date=June 1, 2021 |archive-date=August 19, 2021 |archive-url=https://web.archive.org/web/20210819223738/https://www.academia.edu/2673815|url-status=live }}</ref>

Natural and human-made disasters will disrupt the flow of energy, goods and services. The down-stream customers of those goods and services will, in turn, not be able to produce their product or render their service because they were counting on incoming deliveries "just in time" and so have little or no inventory to work with. The disruption to the economic system will cascade to some degree depending on the nature and severity of the original disaster and may create [[shortages]].<ref>{{Cite news |url=https://www.reuters.com/article/us-japan-supplychain-sp-idUSTRE72K5AL20110321 |title=Special Report: Disasters Show Flaws in Just-in-Time Production |first=Nick Carey, Noel Randewich, Kevin|last=Krolicki|newspaper=Reuters|date=March 21, 2011|via=www.reuters.com|access-date=June 1, 2021|archive-date=June 2, 2021|archive-url=https://web.archive.org/web/20210602220943/https://www.reuters.com/article/us-japan-supplychain-sp-idUSTRE72K5AL20110321|url-status=live}}</ref> The larger the disaster the worse the effect on just-in-time failures. Electrical power is the ultimate example of just-in-time delivery. A severe [[geomagnetic storm]] could disrupt electrical power delivery for hours to years, locally or even globally. Lack of supplies on hand to repair the electrical system would have catastrophic effects.<ref>{{Cite web|url=https://science.nasa.gov/science-news/science-at-nasa/2009/21jan_severespaceweather/|title=Severe Space Weather--Social and Economic Impacts &#124; Science Mission Directorate|website=science.nasa.gov|access-date=June 1, 2021|archive-date=June 2, 2021|archive-url=https://web.archive.org/web/20210602030948/https://science.nasa.gov/science-news/science-at-nasa/2009/21jan_severespaceweather|url-status=live}}</ref>

The [[COVID-19 pandemic#Economics|COVID-19 pandemic]] has caused disruption in JIT practices, with various quarantine restrictions on international trade and commercial activity in general interrupting supply while lacking stockpiles to handle the disruption; along with increased demand for medical supplies like [[personal protective equipment]] (PPE) and ventilators, and even [[panic buying]], including of various domestically manufactured (and so less vulnerable) products like [[panic buying of toilet paper]], disturbing regular demand. This has led to suggestions that stockpiles and diversification of suppliers should be more heavily focused.<ref>{{Cite web|title='Just-in-time' economy out of time as pandemic exposes fatal flaws|url=https://www.abc.net.au/news/2020-05-02/coronavirus-pandemic-exposes-just-in-time-economy/12206776|date=May 1, 2020|website=ABC.net.au |access-date=May 21, 2020|archive-date=May 20, 2020|archive-url=https://web.archive.org/web/20200520151852/https://www.abc.net.au/news/2020-05-02/coronavirus-pandemic-exposes-just-in-time-economy/12206776|url-status=live}}</ref><ref>{{Cite news|title=Companies should shift from 'just in time' to 'just in case'|url=https://www.ft.com/content/606d1460-83c6-11ea-b555-37a289098206|newspaper=Financial Times|date=April 22, 2020|access-date=May 21, 2020|url-access=subscription|archive-date=May 4, 2020|archive-url=https://web.archive.org/web/20200504110301/https://www.ft.com/content/606d1460-83c6-11ea-b555-37a289098206|url-status=live}}</ref><ref>{{Cite web|title=Coronavirus Shows That Supply Chains are Outdated and Unfit For Modern Manufacturing|url=https://www.forbes.com/sites/daveevans/2020/02/18/coronavirus-shows-supply-chains-outdated/|last=Evans|first=Dave|website=Forbes |access-date=May 21, 2020|archive-date=July 22, 2020|archive-url=https://web.archive.org/web/20200722205819/https://www.forbes.com/sites/daveevans/2020/02/18/coronavirus-shows-supply-chains-outdated/|url-status=live}}</ref><ref>{{cite web |last1=Skidelky |first1=Robert |title=The coronavirus pandemic shows why the West must transform its economic logic |url=https://www.newstatesman.com/politics/economy/2020/04/coronavirus-economics-stockpiling-global-supply-chain |website=newstatesman |date=April 22, 2020 |access-date=September 30, 2020 |archive-date=June 2, 2021 |archive-url=https://web.archive.org/web/20210602220016/https://www.newstatesman.com/politics/economy/2020/04/coronavirus-economics-stockpiling-global-supply-chain |url-status=live }}</ref>

Critics of Lean argue that this management method has significant drawbacks, especially for the employees of companies operating under Lean. Common criticism of Lean is that it fails to take into consideration the employee's safety and well-being. Lean manufacturing is associated with an increased level of stress among employees, who have a small margin of error in their work environment which require perfection. Lean also over-focuses on cutting waste, which may lead management to cut sectors of the company that are not essential to the company's short-term productivity but are nevertheless important to the company's legacy. Lean also over-focuses on the present, which hinders a company's plans for the future.<ref name=":critic">{{Cite web|title=What Is the Criticism of Lean Manufacturing?|url=https://www.brighthubpm.com/methods-strategies/105933-criticism-of-lean-manufacturing/|date=February 8, 2011|website=Brighthubpm.com |access-date=May 20, 2020|archive-date=August 15, 2020|archive-url=https://web.archive.org/web/20200815083705/https://www.brighthubpm.com/methods-strategies/105933-criticism-of-lean-manufacturing/|url-status=live}}</ref>

Critics also make negative comparison of Lean and 19th century [[scientific management]], which had been fought by the labor movement and was considered obsolete by the 1930s. Finally, lean is criticized for lacking a standard methodology: "Lean is more a culture than a method, and there is no standard lean production model."<ref name=":critic" />

After years of success of Toyota's Lean Production, the consolidation of supply chain networks has brought Toyota to the position of being the world's biggest carmaker in the rapid expansion. In 2010, the crisis of safety-related problems in Toyota made other carmakers that duplicated Toyota's supply chain system wary that the same recall issue might happen to them.
James Womack had warned Toyota that cooperating with single outsourced suppliers might bring unexpected problems.<ref name="The Economist, 2010">The Economist, 2010, Toyota's overstretched supply chain -The machine that ran too hot :The woes of the world's biggest carmaker are a warning for rivals</ref>

Lean manufacturing is different from lean enterprise. Recent research reports the existence of several lean manufacturing processes but of few lean enterprises.<ref>{{cite web|last1=Nash-Hoff|first1=Michele|title=Why Lean Manufacturers Are Not Lean Enterprises|url=http://www.industryweek.com/blog/lean-sustainability-requires-change-culture|website=Industryweek.com.|date=November 14, 2014 |access-date=May 1, 2015|archive-date=March 27, 2019|archive-url=https://web.archive.org/web/20190327085726/https://www.industryweek.com/blog/lean-sustainability-requires-change-culture|url-status=live}}</ref> One distinguishing feature opposes lean accounting and standard cost accounting. For standard cost accounting, SKUs are difficult to grasp. SKUs include too much hypothesis and variance, i.e., SKUs hold too much indeterminacy. Manufacturing may want to consider moving away from traditional accounting and adopting lean accounting. In using lean accounting, one expected gain is activity-based cost visibility, i.e., measuring the direct and indirect costs at each step of an activity rather than traditional cost accounting that limits itself to labor and supplies.{{citation needed|date=June 2017}}

== See also ==
{{cmn|colwidth=20em|
* [[A3 problem solving]]
* [[Cellular manufacturing]]
* [[Computer-aided lean management]]
* [[CONWIP]]
* [[Efficiency Movement]]
* [[Just in case manufacturing]]
* [[Kaizen]]
* [[Kanban]]
* [[Production flow analysis]]
* [[Takt time]]
}}

== Notes ==

{{reflist}}

== References ==
* Billesbach, Thomas J. 1987. ''Applicability of Just-in-Time Techniques in the Administrative Area''. Doctoral dissertation, University of Nebraska. Ann Arbor, Mich., University Microfilms International.
* Goddard, W. E. 2001. JIT/TQC—identifying and solving problems. ''Proceedings of the 20th Electrical Electronics Insulation Conference'', Boston, October 7–10, 88–91.
* Goldratt, Eliyahu M. and Fox, Robert E. (1986), ''The Race'', North River Press, {{ISBN|0-88427-062-9}}
* Hall, Robert W. 1983. ''Zero Inventories''. Homewood, Ill.: Dow Jones-Irwin.
* Hall, Robert W. 1987. ''Attaining Manufacturing Excellence: Just-in-Time, Total Quality, Total People Involvement''. Homewood, Ill.: Dow Jones-Irwin.
* Hay, Edward J. 1988. ''The Just-in-Time Breakthrough: Implementing the New Manufacturing Basics''. New York: Wiley.
* {{cite journal | last1 = Hohner | first1 = Gregory | year = 1988 | title = JIT/TQC: integrating product design with shop floor effectiveness | journal = Industrial Engineering | volume = 20 | issue = 9| pages = 42–48 |ref=none}}
* {{cite journal | last1 = Hum | first1 = Sin-Hoon | year = 1991 | title = Industrial progress and the strategic significance of JIT and TQC for developing countries | journal = International Journal of Operations & Production Management | volume = 110 | issue = 5| pages = 39–46 | doi = 10.1108/01443579110145320 |ref=none}}
* {{cite book|last1=Hyer|first1=Nancy|last2=Wemmerlov|first2=Urban|title=Reorganizing the Factory: Competing Through Cellular Manufacturing|date=2001|publisher=CRC Press|isbn=9781563272288|url=https://books.google.com/books?id=qfJgCYGRJHgC&pg=PP1|ref=none}}
* {{cite journal | last1 = Jackson | first1 = Paul | year = 1991 | title = White collar JIT at Security Pacific | journal = Target | volume = 7 | issue = 1| pages = 32–37 |ref=none}}
* Ker, J. I., Wang, Y., Hajli, M. N., Song, J., Ker, C. W. (2014). ''Deploying Lean in Healthcare: Evaluating Information Technology Effectiveness in US Hospital Pharmacies''
* Lubben, R. T. 1988. ''Just-in-Time Manufacturing: An Aggressive Manufacturing Strategy''. New York: McGraw-Hill.
* MacInnes, Richard L. (2002) ''The Lean Enterprise Memory Jogger''.
* Mika, Geoffrey L. (1999) ''Kaizen Event Implementation Manual''
* Monden, Yasuhiro. 1982. ''Toyota Production System''. Norcross, Ga: Institute of Industrial Engineers.
* Ohno, Taiichi (1988), ''Toyota Production System: Beyond Large-Scale Production'', Productivity Press, {{ISBN|0-915299-14-3}}
* Ohno, Taiichi (1988), ''Just-In-Time for Today and Tomorrow'', Productivity Press, {{ISBN|0-915299-20-8}}.
* Page, Julian (2003) ''Implementing Lean Manufacturing Techniques''.
* Schonberger, Richard J. 1982. ''Japanese Manufacturing Techniques: Nine Hidden Lessons in Simplicity''. New York: Free Press.
* {{cite book|last1=Shingo|first1=Shingeo|last2=Dillon|first2=Andrew P.|title=A Study of the Toyota Production System: From an Industrial Engineering Viewpoint|date=1989|publisher=CRC Press |isbn=9780915299171|url=https://books.google.com/books?id=RKWU7WElJ7oC&pg=PP1|ref=none}}
* Suri, R. 1986. Getting from 'just in case' to 'just in time': insights from a simple model. 6 (3) 295–304.
* Suzaki, Kyoshi. 1993. ''The New Shop Floor Management: Empowering People for Continuous Improvement''. New York: Free Press.
* Voss, Chris, and David Clutterbuck. 1989. ''Just-in-Time: A Global Status Report''. UK: IFS Publications.
* Wadell, William, and Bodek, Norman (2005), ''The Rebirth of American Industry'', PCS Press, {{ISBN|0-9712436-3-8}}
* {{Cite book |last1=Womack |first1=James P. |last2=Jones |first2=Daniel T. |title=Lean Thinking: Banish Waste and Create Wealth in Your Corporation |date=2003 |publisher=Simon and Schuster |isbn=9781471111006 |url=https://books.google.com/books?id=QZrZAAAAQBAJ&pg=PP1 |access-date=October 2, 2020 |archive-date=October 22, 2021 |archive-url=https://web.archive.org/web/20211022143733/https://books.google.com/books?id=QZrZAAAAQBAJ&pg=PP1 |url-status=live }}
* {{Cite book |last1=Womack |first1=James P. |last2=Jones |first2=Daniel T. |last3=Roos |first3=Daniel |title=The Machine that Changed the World |date=1990 |publisher=Rawson Associates |location=New York |isbn=9780892563500 |url=https://books.google.com/books?id=_n5qRfaNv9AC&pg=PR4 |access-date=October 2, 2020 |archive-date=February 19, 2022 |archive-url=https://web.archive.org/web/20220219163440/https://books.google.com/books?id=_n5qRfaNv9AC&pg=PR4 |url-status=live }}

== External links ==
{{commons category}}
* [https://www.lean.org/ Lean Enterprise Institute]

{{Lean Manufacturing Tools}}
{{Authority control}}

[[Category:Lean manufacturing| ]]
[[Category:Methods of production]]
[[Category:Freight transport]]
[[Category:Inventory]]
[[Category:Working capital management]]
[[Category:Inventory optimization]]