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Lean manufacturing or lean production, which is often known simply as "Lean", is the optimal way of producing goods through the removal of waste and implementing flow, as opposed to batch and queue. For other uses of this term see Industry (disambiguation An industry (from Latin industrius, "diligent industrious" The primary characteristic of batch production is that all components are completed at a workstation before they move to the next one Continuous production is a method used to manufacture, produce or process materials without interruption Job production involves producing a one-off product for a specific customer Total Productive Maintenance is a new way of looking at maintenance or conversely a reversion to old ways but on a mass scale Theory of Constraints (TOC is an overall Management philosophy. Six Sigma is a Business management strategy originally developed by Motorola, that today enjoys wide-spread application in many sectors of industry Reliability-Centered Maintenance, often known as RCM, is an industrial improvement approach focused on identifying and establishing the operational maintenance and capital S88, shorthand for ANSI/ISA-88, is a standard addressing batch process control ANSI/ISA-95, or ISA-95 as it is more commonly referred is an International standard for developing an automated interface between enterprise and control systems Enterprise resource planning ( ERP) is the planning of how business resources (materials employees customers etc IEC 62264 is a International standard for Enterprise-control system integration B2MML or Business To Manufacturing Markup Language is an XML implementation of the ANSI/ ISA -95 family of standards ( ISA-95) known internationally A programmable logic controller ( PLC) or programmable controller is a Digital computer used for Automation of industrial processes such as A distributed control system (DCS refers to a Control system usually of a Manufacturing system, Process or any kind of Dynamic system, Lean manufacturing is a generic process management philosophy derived mostly from the Toyota Production System (TPS). The Toyota Production System (TPS combines management philosophy and practices to form an integrated socio-technical system at Toyota. [1] It is renowned for its focus on reduction of the original Toyota seven wastes in order to improve overall customer value, but there are varying perspectives on how this is best achieved. Muda (無駄 is traditional general Japanese term for activity that is wasteful and doesn't add value or is unproductive etymologically none (無+ Trivia or The steady growth of Toyota, from a small company to the world's largest automaker,[2] has focused attention on how it has achieved this. (pronounced) is a Multinational corporation headquartered in Japan, and is currently the world's largest Automaker.
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For many, Lean is the set of "tools" that assist in the identification and steady elimination of waste (muda). Muda (無駄 is traditional general Japanese term for activity that is wasteful and doesn't add value or is unproductive etymologically none (無+ Trivia or As waste is eliminated quality improves while production time and cost are reduced. Examples of such "tools" are Value Stream Mapping , Five S, Kanban (pull systems), and poka-yoke (error-proofing). Value Stream Mapping is a Lean technique used to analyse the flow of materials and information currently required to bring a product or service to a consumer 5S is a reference to a list of five Japanese words which transliterated and translated into English start with the letter S and are the name of a methodology Kanban (in Kanji 看板 also in Katakana カンバン where kan 看 / カン means "visual" and ban 板 / バン means "card" ( is a Japanese term that means " fail-safing " "Foolproof" or "mistake-proofing" &mdash avoiding ( yokeru) inadvertent errors (
There is a second approach to Lean Manufacturing, which is promoted by Toyota, 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. Mura (斑 or ムラ is traditional general Japanese term for unevenness inconsistency in physical matter or human spiritual condition Techniques to improve flow include production levelling, "pull" production (by means of kanban) and the Heijunka box. Production leveling, also known as production smoothing or – by its Japanese original term – heijunka (平準化 is a technique for reducing the mura Kanban (in Kanji 看板 also in Katakana カンバン where kan 看 / カン means "visual" and ban 板 / バン means "card" A heijunka box is a visual scheduling tool used in Heijunka, a Japanese concept for achieving a smoother production flow This is a fundamentally different approach to most improvement methodologies which may partially account for its lack of popularity.
The difference between these two approaches is not the goal but the prime approach to achieving it. The implementation of smooth flow exposes quality problems which already existed and thus waste reduction naturally happens as a consequence. The advantage claimed for this approach is that it naturally takes a system-wide perspective whereas a waste focus has this perspective, sometimes wrongly, assumed. Some Toyota staff have expressed some surprise at the tool-based approach as they see the tools as work-arounds made necessary where flow could not be fully implemented and not as aims in themselves.
Both Lean and TPS can be seen as a loosely connected set of potentially competing principles whose goal is cost reduction by the elimination of waste. [3] These principles include: Pull processing, Perfect first-time quality, Waste minimization, Continuous improvement, Flexibility, Building and maintaining a long term relationship with suppliers, Autonomation, Load levelling and Production flow and Visual control. Autonomation describes a feature of machine design to effect the principle of jidoka (自働化 used in the Toyota Production System (TPS and Lean manufacturing The disconnected nature of some of these principles perhaps springs from the fact that the TPS has grown pragmatically since 1948 as it responded to the problems it saw within its own production facilities. Thus what one sees today is the result of a 'need' driven learning to improve where each step has built on previous ideas and not something based upon a theoretical framework. Toyota's view is that the main method of Lean is not the tools, but the reduction of three types of waste: muda "non-value-adding work", muri "overburden", and mura "unevenness", to expose problems systematically and to use the tools where the ideal cannot be achieved. Muda (無駄 is traditional general Japanese term for activity that is wasteful and doesn't add value or is unproductive etymologically none (無+ Trivia or Muri ( 無理, “unreasonable” is a Japanese term for overburden unreasonableness or absurdity which has become popularized in the West by its use as a key concept in the Mura (斑 or ムラ is traditional general Japanese term for unevenness inconsistency in physical matter or human spiritual condition Thus the tools are, in their view, workarounds adapted to different situations, which explains any apparent incoherence of the principles above. A workaround is a bypass of a recognized problem in a system A workaround is typically a temporary fix that implies that a genuine solution to the problem is needed
The TPS has two pillar concepts: Just-in-Time (JIT) or "flow", and "autonomation" (smart automation). Autonomation describes a feature of machine design to effect the principle of jidoka (自働化 used in the Toyota Production System (TPS and Lean manufacturing [4] Adherents of the Toyota approach would say that the smooth flowing delivery of value achieves all these improvements as a side-effect. If production flows perfectly then there is no inventory, if customer valued features are the only ones produced then product design is simplified and effort is only expended on features the customer values. The other of the two TPS pillars is the very human aspect of autonomation, whereby automation is achieved with a human touch. [5] This aims to give the machines enough intelligence to recognise when they are working abnormally and flag this for human attention. Thus humans do not have to monitor normal production and only have to focus on abnormal, or fault, conditions. A reduction in human workload that is probably much desired by all involved since it removes much routine and repetitive activity that humans often do not enjoy and where they are therefore not at their most effective.
Lean implementation is therefore focused on getting the right things, to the right place, at the right time, in the right quantity to achieve perfect work flow while minimizing waste and being flexible and able to change. These concepts of flexibility and change are principally required to allow production levelling, using tools like SMED, but have their analogues in other processes such as research and development (R&D). Single Minute Exchange of Die ( SMED) is one of the many Lean production methods for reducing waste in a manufacturing process The phrase research and development (also R and D or more often R&D) according to the Organization for Economic Co-operation and Development, refers The flexibility and ability to change are not open-ended, and therefore often not expensive capability requirements. More importantly, all of these concepts have to be understood, appreciated, and embraced by the actual employees who build the products and therefore own the processes that deliver the value. The cultural and managerial aspects of Lean are just as important as, and possibly more important than, the actual tools or methodologies of production itself. There are many examples of Lean tool implementation without sustained benefit and these are often blamed on weak understanding of Lean in the organization.
Lean aims to make the work simple enough to understand, to do and to manage. To achieve these three at once there is a belief held by some that Toyota's mentoring process (loosely called Senpai and Kohai), is one of the best ways to foster Lean Thinking up and down the organizational structure. and are an essential element of Japanese age-based status relationships similar to the way that family and other relationships are decided based on age with even twins being divided and are an essential element of Japanese age-based status relationships similar to the way that family and other relationships are decided based on age with even twins being divided This is the process undertaken by Toyota as it helps its suppliers to improve their own production. The closest equivalent to Toyota's mentoring process is the concept of "Lean Sensei", which encourages companies, organizations, and teams to seek out outside, third-party experts, who can provide unbiased advice and coaching, (see Womack et al, Lean Thinking, 1998).
Most of the basic goals of lean manufacturing are common sense and documented examples can be seen back to at least Benjamin Franklin. Benjamin Franklin ( April 17 1790 was one of the Founding Fathers of the United States of America. Poor Richard's Almanack says of wasted time, "He that idly loses 5s. worth of time, loses 5s. The shilling is a unit of Currency used in current and former Commonwealth countries and was continued to be used in countries that left the commonwealth , and might as prudently throw 5s. into the river. " He added that avoiding unnecessary costs could be more profitable than increasing sales: "A penny saved is two pence clear. A pin a-day is a groat a-year. Save and have. "
Again Franklin's The Way to Wealth says the following about carrying unnecessary inventory. "You call them goods; but, if you do not take care, they will prove evils to some of you. You expect they will be sold cheap, and, perhaps, they may [be bought] for less than they cost; but, if you have no occasion for them, they must be dear to you. Remember what Poor Richard says, 'Buy what thou hast no need of, and ere long thou shalt sell thy necessaries. ' In another place he says, 'Many have been ruined by buying good penny worths'. " Henry Ford cited Franklin as a major influence on his own business practices, which included Just-in-time manufacturing. Henry Ford ( July 30, 1863 &ndash April 7, 1947) was the American founder of the Ford Motor Company and father of Just-in-time ( JIT) is an inventory strategy implemented to improve the Return on investment of a Business by reducing in-process Inventory and
The concept of waste being built into jobs and then taken for granted was noticed by motion efficiency expert Frank Gilbreth, who saw that masons bent over to pick up bricks from the ground. The bricklayer was therefore lowering and raising his entire upper body to get a 5 pound (2. 3 kg) brick but this inefficiency had been built into the job through long practice. Introduction of a non-stooping scaffold, which delivered the bricks at waist level, allowed masons to work about three times as quickly, and with less effort.
Frederick Winslow Taylor, the father of scientific management, introduced what are now called standardization and best practice deployment. Frederick Winslow Taylor ( 20 March 1856 &ndash 21 March 1915) widely known as F In his Principles of Scientific Management, (1911), Taylor said: "And 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. The Principles of Scientific Management is a monograph published by Frederick Winslow Taylor in 1911 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. "
Taylor also warned explicitly against cutting piece rates (or, by implication, cutting wages or discharging workers) when efficiency improvements reduce the need for raw labor: "…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, the best-known exponent of single minute exchange of die (SMED) and error-proofing or poka-yoke, cites Principles of Scientific Management as his inspiration. born in Saga City, Japan, was a Japanese Industrial engineer who distinguished himself as one of the world’s leading experts on manufacturing practices Single Minute Exchange of Die ( SMED) is one of the many Lean production methods for reducing waste in a manufacturing process Single Minute Exchange of Die ( SMED) is one of the many Lean production methods for reducing waste in a manufacturing process [6]
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. "
Henry Ford continued this focus on waste while developing his mass assembly manufacturing system. Charles Buxton Going wrote in 1915:
Ford, in My Life and Work (1922), provided a single-paragraph description that encompasses the entire concept of waste:
Poor arrangement of the workplace—a major focus of the modern kaizen--and doing a job inefficiently out of habit—are major forms of waste even in modern workplaces.
Ford also pointed out how easy it was to overlook material waste. A former employee, Harry Bennett, wrote:
In other words, Ford saw the rust and realized that the steel plant was not recovering all of the iron.
Design for Manufacture (DFM) also is a Ford concept. Design for manufacturability (DFM is the general engineering art of designing products in such a way that they are easy to manufacture Ford said (in My Life and Work)
The same reference describes just in time manufacturing very explicitly.
While Ford is renowned for his production line it is often not recognized how much effort he put into removing the fitters' work in order to make the production line possible. Until Ford, a car's components always had to be fitted or reshaped by a skilled engineer at the point of use, so that they would connect properly. By enforcing very strict specification and quality criteria on component manufacture, he eliminated this work almost entirely, reducing manufacturing effort by between 60-90%. [9] However, Ford's mass production system failed to incorporate the notion of "pull production" and thus often suffered from over-production.
Toyota's development of ideas that later became Lean may have started at the turn of the 20th century with Sakichi Toyoda, in a textile factory with looms that stopped themselves when a thread broke, this became the seed of autonomation and Jidoka. Sakichi Toyoda (豊田 佐吉 Toyoda Sakichi, February 14 1867 &ndash October 30 1930) was a Japanese inventor and industrialist Autonomation describes a feature of machine design to effect the principle of jidoka (自働化 used in the Toyota Production System (TPS and Lean manufacturing Toyota's journey with JIT may have started back in 1934 when it moved from textiles to produce its first car. Kiichiro Toyoda, founder of Toyota, directed the engine casting work and discovered many problems in their manufacture. Kiichiro Toyoda (豊田喜一郎 'Toyoda Kiichirō' June 11, 1894 – March 27 1952) was a Japanese business man and the son of He decided he must stop the repairing of poor quality by intense study of each stage of the process. In 1936, when Toyota won its first truck contract with the Japanese government, his processes hit new problems and he developed the "Kaizen" improvement teams. Kaizen ( 改善, Japanese for "continuous improvement" is a Japanese philosophy that focuses on continuous improvement throughout all aspects
Levels of demand in the Post War economy of Japan were low and the focus of mass production on lowest cost per item via economies of scale therefore had little application. Having visited and seen supermarkets in the USA, Taiichi Ohno recognised 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 (build to order rather than target driven Push) came to underpin production scheduling.
It was with Taiichi Ohno at Toyota that these themes came together. is considered to be the father of the Toyota Production System, also known as Lean Manufacturing. He built on the already existing internal schools of thought and spread their breadth and use into what has now become the Toyota Production System (TPS). The Toyota Production System (TPS combines management philosophy and practices to form an integrated socio-technical system at Toyota. It is principally from the TPS, but now including many other sources, that Lean production is developing. Norman Bodek wrote the following in his foreword to a reprint of Ford's Today and Tomorrow:
While the elimination of waste seem like a simple and clear subject it is noticeable that waste is often very conservatively identified. This then hugely reduces the potential of such an aim. The elimination of waste is the goal of Lean, and Toyota defined three types of waste: muda, muri and mura. Muda (無駄 is traditional general Japanese term for activity that is wasteful and doesn't add value or is unproductive etymologically none (無+ Trivia or Muri ( 無理, “unreasonable” is a Japanese term for overburden unreasonableness or absurdity which has become popularized in the West by its use as a key concept in the Mura (斑 or ムラ is traditional general Japanese term for unevenness inconsistency in physical matter or human spiritual condition
To illustrate the state of this thinking Shigeo Shingo observed that only the last turn of a bolt that tightens it—the rest is just movement. born in Saga City, Japan, was a Japanese Industrial engineer who distinguished himself as one of the world’s leading experts on manufacturing practices This ever finer clarification of waste is key to establishing distinctions between value-adding activity, waste and non-value-adding work. [10] Non-value adding work is waste that must be done under the present work conditions. One key is to measure, or estimate, the size of these wastes, in order to demonstrate the effect of the changes achieved and therefore the movement towards the goal.
The "flow" (or smoothness) based approach aims to achieve JIT, by removing the variation caused by work scheduling and thereby provide a driver, rationale or target and priorities for implementation, using a variety of techniques. The effort to achieve JIT exposes many quality problems that are hidden by buffer stocks; by forcing smooth flow of only value-adding steps, these problems become visible and must be dealt with explicitly.
Muri is all the unreasonable work that management imposes on workers and machines because of poor organization, such as carrying heavy weights, moving things around, dangerous tasks, even working significantly faster than usual. It is pushing a person or a machine beyond its natural limits. This may simply be asking a greater level of performance from a process than it can handle without taking shortcuts and informally modifying decision criteria. Unreasonable work is almost always a cause of multiple variations.
To link these three concepts is straightforward. Firstly, muri focuses on the preparation and planning of the process, or what work can be avoided proactively by design. Next, mura then focuses on implementation and the elimination of fluctuation at the scheduling or operations level, such as quality and volume. Muda is discovered after the process is in place and is dealt with reactively. It is seen through variation in output. It is the role of management to examine the muda, in the processes and eliminate the deeper causes by considering the connections to the muri and mura of the system. The muda and mura inconsistencies must be fed back to the muri, or planning, stage for the next project.
A typical example of the interplay of these wastes is the corporate behaviour of "making the numbers" as the end of a reporting period approaches. Demand is raised, increasing (mura), when the "numbers" are low which causes production to try to squeeze extra capacity from the process which causes routines and standards to be modified or stretched. This stretch and improvisation leads to muri-style waste which leads to downtime, mistakes and backflows and waiting, thus the muda of waiting, correction and movement.
The original seven muda are:
Some of these definitions may seem rather idealistic, but this tough definition is seen as important. The clear identification of non-value-adding work, as distinct from wasted work, is critical to identifying the assumptions behind the current work process and to challenging them in due course. [12] Breakthroughs in SMED and other process changing techniques rely upon clear identification of where untapped opportunities may lie if the processing assumptions are challenged. Single Minute Exchange of Die ( SMED) is one of the many Lean production methods for reducing waste in a manufacturing process
Lean is about more than just cutting costs in the factory. One crucial insight is that most costs are assigned when a product is designed, (see Genichi Taguchi). Gen'ichi Taguchi (田口 玄- Taguchi Genichi (born January 1, 1924 in Tokamachi, Japan) is an Engineer and Statistician Often an engineer will specify familiar, safe materials and processes rather than inexpensive, efficient ones. This reduces project risk, that is, the cost to the engineer, while increasing financial risks, and decreasing profits. Good organizations develop and review checklists to review product designs.
Companies must often look beyond the shop-floor to find opportunities for improving overall company cost and performance. At the system engineering level, requirements are reviewed with marketing and customer representatives to eliminate those requirements which are costly. Systems engineering is an Interdisciplinary field of Engineering that focuses on how complex engineering projects should be designed and managed Shared modules may be developed, such as multipurpose power supplies or shared mechanical components or fasteners. Requirements are assigned to the cheapest discipline. For example, adjustments may be moved into software, and measurements away from a mechanical solution to an electronic solution. Another approach is to choose connection or power-transport methods that are cheap or that used standardized components that become available in a competitive market.
In summary, an example of a lean implementation program could be:-
With a tools based approach
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With a muri or flow based approach (as used in the TPS with suppliers[13]).
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The role of the leaders within the organization is the fundamental element of sustaining the progress of lean thinking. A workcell is an arrangement of resources in a manufacturing environment to improve the quality speed and cost of the process A manufacturing supermarket (or market location is for a factory process what a retail supermarket is for the customer Kanban (in Kanji 看板 also in Katakana カンバン where kan 看 / カン means "visual" and ban 板 / バン means "card" Experienced kaizen members at Toyota, for example, often bring up the concepts of Senpai, Kohai, and Sensei, because they strongly feel that transferring of Toyota culture down and across the Toyota can only happen when more experienced Toyota Sensei continuously coach and guide the less experienced lean champions. and are an essential element of Japanese age-based status relationships similar to the way that family and other relationships are decided based on age with even twins being divided and are an essential element of Japanese age-based status relationships similar to the way that family and other relationships are decided based on age with even twins being divided is a Japanese title used to refer to or address teachers professionals such as lawyers and doctors politicians clergymen and other authority figures Unfortunately, most lean practitioners in North America focus on the tools and methodologies of lean, versus the philosophy and culture of lean. Some exceptions include Shingijitsu Consulting out of Japan, which is made up of ex-Toyota managers, and Lean Sensei International based in North America, which coaches lean through Toyota-style cultural experience.
One of the dislocative effects of Lean is in the area of key performance indicators (KPI). Key Performance Indicators ( KPI) are financial and non-financial Metrics used to help an organization define and measure progress toward organizational goals The KPIs by which a plant/facility are judged will often be driving behaviour, because the KPIs themselves assume a particular approach to the work being done. This can be an issue where, for example a truly Lean, Fixed Repeating Schedule (FRS) and JIT approach is adopted, because these KPIs will no longer reflect performance, as the assumptions on which they are based become invalid. Fixed Repeating Schedule is a key element of the Toyota Production System and Lean Manufacturing. It is a key leadership challenge to manage the impact of this KPI chaos within the organization. A set of performance metrics which is considered to fit well in a Lean environment is Overall Equipment Effectiveness, or OEE.
Similarly, commonly-used accounting systems developed to support mass production are no longer appropriate for companies pursuing Lean. Mass production (also called flow production, repetitive flow production, series production, or serial production) is the production of Lean Accounting provides truly Lean approaches to business management and financial reporting. Lean accounting is Accounting for the lean enterprise It seeks to move from traditional cost accounting to a system that measures and motivates good business practices
Key focus areas for leaders are
Whilst Lean is seen by many as a generalization of the Toyota Production System into other industries and contexts there are some acknowledged differences that seem to have developed in implementation. PDCA (" Plan-Do-Check-Act " is an iterative four-step problem-solving process typically used in Quality control. Genchi Genbutsu (現地現物 means "go and see for yourself" and it is an integral part of the Toyota Production System. The Toyota Production System (TPS combines management philosophy and practices to form an integrated socio-technical system at Toyota.
Lean, as a concept or brand, has captured the imagination of many in different spheres of activity. Examples of these from many sectors are listed below.
Lean principles have been successfully applied to call center services to improve live agent call handling. By combining Agent-assisted Voice Solutions and Lean's waste reduction practices, a company reduced handle time, reduced between agent variablity, reduced accent bariers, and attained near perfect process adherence. [14]
A study conducted on behalf of the Scottish Executive, by Warwick University, in 2005/06 found that Lean methods were applicable to the public sector, but that most results had been achieved using a much more restricted range of techniques than Lean provides. [15]
The challenge in moving Lean to services is the lack of widely available reference implementations to allow people to see how it 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. It is also the case that the manufacturing examples of 'techniques' or 'tools' need to be 'translated' into a service context 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 engineers of Toyota. This places huge importance upon sponsorship to encourage and protect these experimental developments.
JIT is the most used and recognized lean manufacturing technique. For many years just-in-time has been misused or misunderstood for many American manufacturing companies. According to the book, "Running Today's Factory", some people think that JIT means Just Implement Techniques, in other words, use "best practices". The correct definition of just-in-time is having the right part at the right place in the right amount at the right time. This technique shortens cycle times, decreases the amount of inventory that a company carries, leads to low work-in-process (WIP), and creates a flexible atmosphere for the type or amount of product that a company would like to run and most of all streamlines work flow through a manufacturing facility. [16]
Those areas below are linked to this subject:
Closely related methodologiesTerminology |
Areas of implementation outside Production
Other
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