![Lean Manufacturing:
Lean manufacturing or lean production, often simply "lean", is a systematic method for the
elimination of waste ("Muda") within a manufacturing system. Lean also takes into account
waste created through overburden ("Muri") and waste created through unevenness in workloads
("Mura")
Working from the perspective of the client who consumes a product or service, "value" is any action
or process that a customer would be willing to pay for.
Essentially, lean is centered on making obvious what adds value by reducing everything else. Lean
manufacturing is a management philosophy derived mostly from the Toyota Production
System (TPS) (hence the term Toyotism is also prevalent) and identified as "lean" only in the
1990s.[1][2]
TPS is renowned for its focus on reduction of the original Toyota seven wastes to improve
overall customer value, but there are varying perspectives on how this is best achieved. The steady
growth of Toyota, from a small company to the world's largest automaker,[3]
has focused attention on
how it has achieved this success.
TPS
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. Toyota's journey with just-in-time (JIT)
may have started back in 1934 when it moved from textiles to produce its first car. Kiichiro Toyoda,
founder of Toyota Motor Corporation, directed the engine casting work and discovered many
problems in their manufacture. 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.
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.](https://image.slidesharecdn.com/ff9ff688-217f-4235-927e-1e8d2a4d94ff-160620053121/85/LEAN-Manufacturing-1-320.jpg)
![It was with Taiichi Ohno at Toyota that these themes came together. 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). It is principally from the TPS (which was widely referred to in the 1980s
as just-in-time manufacturing), 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:
I was first introduced to the concepts of just-in-time (JIT) and the Toyota production system
in 1980. Subsequently I had the opportunity to witness its actual application at Toyota on one
of our numerous Japanese study missions. There I met Mr. Taiichi Ohno, the system's
creator. When bombarded with questions from our group on what inspired his thinking, he
just laughed and said he learned it all from Henry Ford's book." The scale, rigor and
continuous learning aspects of TPS have made it a core concept of lean.
Types of waste
Although the elimination of waste may 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 broad types of
waste: muda, muri and mura; it should be noted that for many lean implementations this list
shrinks to the first waste type only with reduced corresponding benefits. To illustrate the state of
this thinking Shigeo Shingo observed that only the last turn of a bolt tightens it—the rest is just
movement. This ever finer clarification of waste is key to establishing distinctions between value-
adding activity, waste and non-value-adding work.[18]
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, to demonstrate the effect of the changes achieved and therefore the movement
toward 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](https://image.slidesharecdn.com/ff9ff688-217f-4235-927e-1e8d2a4d94ff-160620053121/85/LEAN-Manufacturing-2-320.jpg)
![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 simple in TPS and thus lean. 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 how the work design is implemented and the elimination of
fluctuation at the scheduling or operations level, such as quality and volume. Muda is then
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 themuri 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 to 'make plan,'
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
back flows, and waiting, thus the muda of waiting, correction and movement.
The original sevenmuda are:
Transport (movingproducts that are not actually requiredto perform the processing)
Inventory(all components, work in process,and finishedproductnot beingprocessed)
Motion(people or equipmentmovingor walking more than isrequiredto performthe
processing)
Waiting(waitingfor the nextproduction step,interruptionsof production duringshift change)
Overproduction(productionahead of demand)
Over Processing(resultingfrompoor tool or product designcreatingactivity)
Defects(the effortinvolvedin inspectingforand fixing defects)[19]
Taking the first letter of each waste, the acronym "TIMWOOD" is formed. This is a common way
to remember the 7 "muda".
Later an eighth waste was defined by Womack et al. (2003); it was described as manufacturing
goods or services that do not meet customer demand or specifications. Many others have added
the "waste of unused human talent" to the original seven wastes. For example, six
sigma includes the waste of Skills, referred to as "under-utilizing capabilities and delegating
tasks with inadequate training". Other additional wastes added were for example "space". These
wastes were not originally a part of the seven deadly wastes defined by Taiichi Ohno in TPS, but
were found to be useful additions in practice. In 1999 Geoffrey Mika in his book, "Kaizen Event](https://image.slidesharecdn.com/ff9ff688-217f-4235-927e-1e8d2a4d94ff-160620053121/85/LEAN-Manufacturing-3-320.jpg)
![Implementation Manual" added three more forms of waste that are now universally accepted;
The waste associated with working to the wrong metrics or no metrics, the waste associated with
not utilizing a complete worker by not allowing them to contribute ideas and suggestions and be
part of Participative Management, and lastly the waste attributable to improper use of
computers; not having the proper software, training on use and time spent surfing, playing
games or just wasting time. For a complete listing of the "old" and "new" wastes see Bicheno
and Holweg (2009)[20]
Some of these definitions may seem rather idealistic, but this tough definition is seen as
important and they drove the success of TPS. 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.[21]
Breakthroughs in SMED and other process
changing techniques rely upon clear identification of where untapped opportunities may lie if the
processing assumptions are challenged.
The discipline required to implement lean and the disciplines it seems to require are so often
counter-cultural that they have made successful implementation of lean a major challenge.
Some would say that it was a major challenge in its manufacturing 'heartland' as well.
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
An example program
In summary, an example of a lean implementation program could be:
With a tools-based approach
Senior management to agree
and discuss their lean vision
Management brainstorm to
identify project leader and set
objectives
Communicate plan and vision
to the workforce
Ask for volunteers to form the
lean implementation team (5-7
With a muri or flow based approach (as used in the
TPS with suppliers).[24]
Sort out as many of the visible quality
problems as you can, as well as downtime
and other instability problems, and get the
internal scrap acknowledged and its
management started.
Make the flow of parts through the system
or process as continuous as possible
using workcells and market locations where](https://image.slidesharecdn.com/ff9ff688-217f-4235-927e-1e8d2a4d94ff-160620053121/85/LEAN-Manufacturing-4-320.jpg)
LEAN Manufacturing
- 1. Lean Manufacturing: Lean manufacturing or lean production, often simply "lean", is a systematic method for the elimination of waste ("Muda") within a manufacturing system. Lean also takes into account waste created through overburden ("Muri") and waste created through unevenness in workloads ("Mura") Working from the perspective of the client who consumes a product or service, "value" is any action or process that a customer would be willing to pay for. Essentially, lean is centered on making obvious what adds value by reducing everything else. Lean manufacturing is a management philosophy derived mostly from the Toyota Production System (TPS) (hence the term Toyotism is also prevalent) and identified as "lean" only in the 1990s.[1][2] TPS is renowned for its focus on reduction of the original Toyota seven wastes to improve overall customer value, but there are varying perspectives on how this is best achieved. The steady growth of Toyota, from a small company to the world's largest automaker,[3] has focused attention on how it has achieved this success. TPS 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. Toyota's journey with just-in-time (JIT) may have started back in 1934 when it moved from textiles to produce its first car. Kiichiro Toyoda, founder of Toyota Motor Corporation, directed the engine casting work and discovered many problems in their manufacture. 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. 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.
- 2. It was with Taiichi Ohno at Toyota that these themes came together. 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). It is principally from the TPS (which was widely referred to in the 1980s as just-in-time manufacturing), 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: I was first introduced to the concepts of just-in-time (JIT) and the Toyota production system in 1980. Subsequently I had the opportunity to witness its actual application at Toyota on one of our numerous Japanese study missions. There I met Mr. Taiichi Ohno, the system's creator. When bombarded with questions from our group on what inspired his thinking, he just laughed and said he learned it all from Henry Ford's book." The scale, rigor and continuous learning aspects of TPS have made it a core concept of lean. Types of waste Although the elimination of waste may 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 broad types of waste: muda, muri and mura; it should be noted that for many lean implementations this list shrinks to the first waste type only with reduced corresponding benefits. To illustrate the state of this thinking Shigeo Shingo observed that only the last turn of a bolt tightens it—the rest is just movement. This ever finer clarification of waste is key to establishing distinctions between value- adding activity, waste and non-value-adding work.[18] 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, to demonstrate the effect of the changes achieved and therefore the movement toward 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
- 3. 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 simple in TPS and thus lean. 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 how the work design is implemented and the elimination of fluctuation at the scheduling or operations level, such as quality and volume. Muda is then 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 themuri 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 to 'make plan,' 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 back flows, and waiting, thus the muda of waiting, correction and movement. The original sevenmuda are: Transport (movingproducts that are not actually requiredto perform the processing) Inventory(all components, work in process,and finishedproductnot beingprocessed) Motion(people or equipmentmovingor walking more than isrequiredto performthe processing) Waiting(waitingfor the nextproduction step,interruptionsof production duringshift change) Overproduction(productionahead of demand) Over Processing(resultingfrompoor tool or product designcreatingactivity) Defects(the effortinvolvedin inspectingforand fixing defects)[19] Taking the first letter of each waste, the acronym "TIMWOOD" is formed. This is a common way to remember the 7 "muda". Later an eighth waste was defined by Womack et al. (2003); it was described as manufacturing goods or services that do not meet customer demand or specifications. Many others have added the "waste of unused human talent" to the original seven wastes. For example, six sigma includes the waste of Skills, referred to as "under-utilizing capabilities and delegating tasks with inadequate training". Other additional wastes added were for example "space". These wastes were not originally a part of the seven deadly wastes defined by Taiichi Ohno in TPS, but were found to be useful additions in practice. In 1999 Geoffrey Mika in his book, "Kaizen Event
- 4. Implementation Manual" added three more forms of waste that are now universally accepted; The waste associated with working to the wrong metrics or no metrics, the waste associated with not utilizing a complete worker by not allowing them to contribute ideas and suggestions and be part of Participative Management, and lastly the waste attributable to improper use of computers; not having the proper software, training on use and time spent surfing, playing games or just wasting time. For a complete listing of the "old" and "new" wastes see Bicheno and Holweg (2009)[20] Some of these definitions may seem rather idealistic, but this tough definition is seen as important and they drove the success of TPS. 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.[21] Breakthroughs in SMED and other process changing techniques rely upon clear identification of where untapped opportunities may lie if the processing assumptions are challenged. The discipline required to implement lean and the disciplines it seems to require are so often counter-cultural that they have made successful implementation of lean a major challenge. Some would say that it was a major challenge in its manufacturing 'heartland' as well. 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 An example program In summary, an example of a lean implementation program could be: With a tools-based approach Senior management to agree and discuss their lean vision Management brainstorm to identify project leader and set objectives Communicate plan and vision to the workforce Ask for volunteers to form the lean implementation team (5-7 With a muri or flow based approach (as used in the TPS with suppliers).[24] Sort out as many of the visible quality problems as you can, as well as downtime and other instability problems, and get the internal scrap acknowledged and its management started. Make the flow of parts through the system or process as continuous as possible using workcells and market locations where
- 5. works best, all from different departments) Appoint members of the lean manufacturing implementation team Train the Implementation Team in the various lean tools - make a point of trying to visit other non competing businesses that have implemented lean Select a Pilot Project to implement – 5S is a good place to start Run the pilot for 2–3 months - evaluate, review and learn from your mistakes Roll out pilot to other factory areas Evaluate results, encourage feedback Stabilize the positive results by teaching supervisors how to train the new standards you've developed with TWI methodology (Training Within Industry) Once you are satisfied that you have a habitual program, consider introducing the next lean tool. Select the one that gives you the biggest return for your business. necessary and avoiding variations in the operators work cycle Introduce standard work and stabilize the work pace through the system Start pulling work through the system, look at the production scheduling and move toward daily orders withkanban cards Even out the production flow by reducing batch sizes, increase delivery frequency internally and if possible externally, level internal demand Improve exposed quality issues using the tools Remove some people (or increase quotas) and go through th
- 6. Lean leadership The role of the leaders within the organization is the fundamental element of sustaining the progress of lean thinking. 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 Toyota can only happen when more experienced Toyota Sensei continuously coach and guide the less experienced lean champions. One of the dislocative effects of lean is in the area of key performance indicators (KPI). The KPIs by which a plant/facility are judged will often be driving behavior, 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. It is a key leadership challenge to manage the impact of this KPI chaos within the organization. Similarly, commonly used accounting systems developed to support mass production are no longer appropriate for companies pursuing lean. Lean accounting provides truly lean approaches to business management and financial reporting. After formulating the guiding principles of its lean manufacturing approach in the Toyota Production System (TPS), Toyota formalized in 2001 the basis of its lean management: the key managerial values and attitudes needed to sustain continuous improvement in the long run. These core management principles are articulated around the twin pillars of Continuous Improvement (relentless elimination of waste) and Respect for People (engagement in long term relationships based on continuous improvement and mutual trust). This formalization stems from problem solving. As Toyota expanded beyond its home base for the past 20 years, it hit the same problems in getting TPS properly applied that other western companies have had in copying TPS. Like any other problem, it has been working on trying a series of countermeasures to solve this particular concern. These countermeasures have focused on culture: how people behave, which is the most difficult challenge of all. Without the proper behavioral principles and values, TPS can be totally misapplied and fail to deliver results. As with TPS, the values had originally been passed down in a master-disciple manner, from boss to subordinate, without any written statement on the way. Just as with TPS, it was internally argued that formalizing the values would stifle them and lead to further misunderstanding. However, as Toyota veterans eventually wrote down the basic principles of TPS, Toyota set to put the Toyota Way into writing to educate new joiners.
- 7. Continuous Improvement breaks down into 3 basic principles: 1. Challenge: Having a long term vision of the challenges one needs to face to realize one's ambition (what we need to learn rather than what we want to do and then having the spirit to face that challenge). To do so, we have to challenge ourselves every day to see if we are achieving our goals. 2. Kaizen: Good enough never is, no process can ever be thought perfect, so operations must be improved continuously, striving for innovation and evolution. 3. Genchi Genbutsu: Going to the source to see the facts for oneself and make the right decisions, create consensus, and make sure goals are attained at the best possible speed. Respect for People is less known outside of Toyota, and essentially involves 2 defining principles: 1. Respect: Taking every stakeholders' problems seriously, and making every effort to build mutual trust. Taking responsibility for other people reaching their objectives. 2. Teamwork: This is about developing individuals through team problem-solving. The idea is to develop and engage people through their contribution to team performance. Shop floor teams, the whole site as team, and team Toyota at the outset. Stepstoachieveleansystems The following steps should be implemented to create the ideal lean manufacturing system: Designa simple manufacturing system Recognize that there is always roomfor improvement Continuously improve the leanmanufacturing systemdesign
- 8. Design a simple manufacturing system A fundamental principle of lean manufacturing is demand-based flow manufacturing. In this type of production setting, inventory is only pulled through each production center when it is needed to meet a customer's order. The benefits of this goal include: Decreasedcycle time Less inventory Increasedproductivity Increasedcapital equipmentutilization -Abu Zafar Ansari Bin Kayes Akik