Lean manufacturing
Lean manufacturing adopts the just-in-time approach and additionally focuses on reducing cycle, flow, and throughput times by further eliminating activities that do not add any value for the customer.
The downside is that it requires producers to forecast demand accurately as the benefits can be nullified by minor delays in the supply chain.
Frederick Taylor and Henry Ford documented their observations relating to these topics, and Shigeo Shingo and Taiichi Ohno applied their enhanced thoughts on the subject at Toyota in the late 1940s after World War II.
[7] 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.
[8][9][10][11] 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.
During Japan's post–World War II rebuilding (of economy, infrastructure, industry, political, and social-emotional stability): Thus, the Japanese "leaned out" their processes.
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.
[18] 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.
[22] Among the best known of MRP II's advocates was George Plossl, who authored two articles questioning just-in-time's kanban planning method[23] and the "japanning of America".
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.
[28] 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,[29] 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".
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).
The same period, saw the rise of books and articles with similar concepts and methodologies but with alternative names, including cycle time management,[35] time-based competition,[36] quick-response manufacturing,[37] flow,[38] and pull-based production systems.
A 1993 book on "world-class distribution logistics" discusses kanban links from factories onward,[40] and a manufacturer-to-retailer model developed in the U.S. in the 1980s, referred to as quick response,[41] has morphed over time to what is called fast fashion.
Four different notions of lean have been identified:[44] The other way to avoid market risk and control the supply efficiently is to cut down in stock.
[45] In 1999, Spear and Bowen[46] identified four rules which characterize the "Toyota DNA": 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.
[48] Sepheri provides a list of methodologies of just-in-time manufacturing that "are important but not exhaustive":[49] 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:[50] Lean is founded on the concept of continuous and incremental improvements on product and process while eliminating redundant activities.
[64] 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.
[65][need quotation to verify], [66] 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.
[68] 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.
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.
[71][need quotation to verify] Lean principles also have applications to software development and maintenance as well as other sectors of information technology (IT).
[74] 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.
[77] Due to the intensively competitive environment, lean approach becomes a growing alternative in the healthcare sector to achieve optimized resource management and performance improvement.
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.
[82] The 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.
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.
[87] 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.
