View
224
Download
0
Category
Preview:
Citation preview
8/2/2019 Lean Manufacturing or Lean Production Operation Management
1/5
What is Lean Manufacturing?
Lean manufacturing or lean production, often simply, "Lean," is a production practice that
considers the expenditure of resources for any goal other than the creation of value for theend customer to be wasteful, and thus a target for elimination.
Lean manufacturing is a management philosophy derived mostly from the ToyotaProduction System (TPS) (hence the term Toyotism is also prevalent) and identified as
"Lean" only in the 1990s.[1][2] It is renowned for its focus on reduction of the original
Toyota seven wastes to improve overall customer value, but there are varying perspectiveson 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.
Lean manufacturing is a variation on the theme of efficiency based on optimizing flow; it isa present-day instance of the recurring theme in human history toward increasing
efficiency, decreasing waste, and using empirical methods to decide what matters, rather
than uncritically accepting pre-existing ideas. As such, it is a chapter in the larger narrativethat also includes such ideas as the folk wisdom of thrift, time and motion study,
Taylorism, the Efficiency Movement, and Fordism. Lean manufacturing is often seen as a
more refined version of earlier efficiency efforts, building upon the work of earlier leaderssuch as Taylor or Ford, and learning from their mistakes.
History:
Lean principles come from the Japanesemanufacturing industry. The term was
first coined by John Krafcik in a Fall1988 article, "Triumph of the LeanProduction System," published in the
Sloan Management Review and based on
his master's thesis at the MIT SloanSchool of Management.[4] Krafcik had
been a quality engineer in the Toyota-GM
NUMMI joint venture in Californiabefore coming to MIT for MBA studies.
Krafcik's research was continued by the
International Motor Vehicle Program
(IMVP) at MIT, which produced theinternational best-seller book co-authored
by Jim Womack, Daniel Jones, and
Daniel Roos called The Machine ThatChanged the World.[1] A complete
historical account of the IMVP and how
the term "lean" was coined is given byHolweg (2007).[2] For many, Lean is the
http://en.wikipedia.org/wiki/Sloan_Management_Reviewhttp://en.wikipedia.org/wiki/MIT_Sloan_School_of_Managementhttp://en.wikipedia.org/wiki/MIT_Sloan_School_of_Managementhttp://en.wikipedia.org/wiki/Lean_manufacturing#cite_note-3http://en.wikipedia.org/wiki/International_Motor_Vehicle_Programhttp://en.wikipedia.org/wiki/Lean_manufacturing#cite_note-womack-0http://en.wikipedia.org/wiki/Lean_manufacturing#cite_note-Holweg_2007_420.E2.80.93437-1http://en.wikipedia.org/wiki/Sloan_Management_Reviewhttp://en.wikipedia.org/wiki/MIT_Sloan_School_of_Managementhttp://en.wikipedia.org/wiki/MIT_Sloan_School_of_Managementhttp://en.wikipedia.org/wiki/Lean_manufacturing#cite_note-3http://en.wikipedia.org/wiki/International_Motor_Vehicle_Programhttp://en.wikipedia.org/wiki/Lean_manufacturing#cite_note-womack-0http://en.wikipedia.org/wiki/Lean_manufacturing#cite_note-Holweg_2007_420.E2.80.93437-18/2/2019 Lean Manufacturing or Lean Production Operation Management
2/5
set of "tools" that assist in the identification and steady elimination of waste (muda). 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), andpoka-yoke(error-proofing).
Lean implementation is therefore focused on getting the right things to the right place at theright 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 principallyrequired to allow production leveling, using tools like SMED, but have their analogues in
other processes such as research and development (R&D). The flexibility and ability to
change are within bounds and not open-ended, and therefore often not expensive capabilityrequirements. 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 possiblymore 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 throughout the whole organization.
Lean aims to make the work simple enough to understand, do and manage. To achievethese three goals at once there is a belief held by some that Toyota's mentoring process,
(loosely calledSenpai andKohai), which is Japanese for senior and junior, is one of the
best ways to foster Lean Thinking up and down the organizational structure. This is theprocess undertaken by Toyota as it helps its suppliers 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 outside, third-party experts, who
can provide unbiased advice and coaching, (see Womack et al., Lean Thinking, 1998).
Steps to achieve lean systems
The following steps should be implemented to create the ideal lean manufacturing system:
1. Design a simple manufacturing system
2. Recognize that there is always room for improvement3. Continuously improve the lean manufacturing system design
Advantages of Lean Manufacturing
Time Savings
http://en.wikipedia.org/wiki/Muda_(Japanese_term)http://en.wikipedia.org/wiki/Value_Stream_Mappinghttp://en.wikipedia.org/wiki/5S_(methodology)http://en.wikipedia.org/wiki/Kanbanhttp://en.wikipedia.org/wiki/Poka-yokehttp://en.wikipedia.org/wiki/SMEDhttp://en.wikipedia.org/wiki/Research_and_developmenthttp://en.wikipedia.org/wiki/Senpaihttp://en.wikipedia.org/wiki/Senpaihttp://en.wikipedia.org/wiki/Kohaihttp://en.wikipedia.org/w/index.php?title=Lean_Sensei&action=edit&redlink=1http://en.wikipedia.org/wiki/Muda_(Japanese_term)http://en.wikipedia.org/wiki/Value_Stream_Mappinghttp://en.wikipedia.org/wiki/5S_(methodology)http://en.wikipedia.org/wiki/Kanbanhttp://en.wikipedia.org/wiki/Poka-yokehttp://en.wikipedia.org/wiki/SMEDhttp://en.wikipedia.org/wiki/Research_and_developmenthttp://en.wikipedia.org/wiki/Senpaihttp://en.wikipedia.org/wiki/Kohaihttp://en.wikipedia.org/w/index.php?title=Lean_Sensei&action=edit&redlink=18/2/2019 Lean Manufacturing or Lean Production Operation Management
3/5
Assume a worker on an assembly line must use two different sockets to do herjob. If it
takes the worker 10 seconds to change the sockets on the ratchet, then that 10 seconds
is wasted, because it was not spent actually making the product. If the worker mustchange the sockets hundreds of times per day, then that means she spends several
thousand seconds out of her day just changing sockets.
Quality Control
In the past, manufacturers had quality inspectors who inspected final products thatcame off the assembly lines. Lean has evolved from Total Quality Management and
seeks to build quality into the process.
Saves Money
The two aforementioned traits of lean manufacturing both lend to the money savingsthat lean helps to accomplish. But, lean as adapted to aculture as a whole creates an
environment that strives to eliminate all waste, whether it is waste in steps, material, orspending.
Saves Space
In the drive for eliminating waste, lean manufacturing is focused around workspace
layout. By organizing workspace and keeping the appropriate tools within reach, lean
manufacturing saves space. One example of lean manufacturing is "5S", which works
to separate tools and place each item in a "home" so that it is always easy to find.
Continuous Improvement
Lean manufacturers never rest on their accomplishments; rather they strive to
continually improve their process.
Disadvantages of Lean Manufacturing
Supply Problems
Because only a small amount of inventory is kept on hand, lean manufacturing depends
heavily on suppliers that can provide products for the manufacturing process
http://www.ehow.com/careers/http://www.ehow.com/culture-and-society/http://www.ehow.com/culture-and-society/http://www.ehow.com/careers/http://www.ehow.com/culture-and-society/8/2/2019 Lean Manufacturing or Lean Production Operation Management
4/5
dependably and without interruption. Problems like employee strikes, transportation
delays and quality errors on the part of suppliers can create manufacturing holdups that
can be fatal.
High Cost of Implementation
Implementing lean manufacturing often means completely dismantling previous
physical plant setups and systems.
Lack of Acceptance by Employees
Lean manufacturing processes require a complete overhaul of manufacturing systemsthat may cause stress and rejection by employees who prefer old ways of doing things.
Moreover, lean manufacturing requires constant employee input on quality control,
which some employees may feel disinclined or unqualified to do.
Customer Dissatisfaction Problems
Because lean manufacturing processes are so dependent on supplier efficiency, any
disruption in the supply chain--and therefore, on production--can be a problem that
adversely affects customers. Delivery delays can cause long-lasting marketingproblems that can be difficult to overcome.
ConclusionLean manufacturing and more generally lean enterprise work principles are widely taughtthroughout most industries now, and yet there are still companies that persistently refuse to
embrace the ideas. With the prevalence of lean ideas and books it is amazing to see that as
recently as 2005, polls among manufacturing managers showed that 41% of them admitted
to little understanding of what lean was. Another 34% were familiar with the term but didnot really know how to achieve it. 22% replied that their companies were on the lean
8/2/2019 Lean Manufacturing or Lean Production Operation Management
5/5
path but not getting the desired results, and only 3% were undergoing lean transformations
with great results (Koenigsaecker 2005).
Bibliography:http://en.wikipedia.org/wiki/Lean_manufacturing
http://www.ehow.com/about_5418429_advantages-disadvantages-lean-production.html
http://en.wikipedia.org/wiki/Lean_manufacturinghttp://www.ehow.com/about_5418429_advantages-disadvantages-lean-production.htmlhttp://en.wikipedia.org/wiki/Lean_manufacturinghttp://www.ehow.com/about_5418429_advantages-disadvantages-lean-production.htmlRecommended