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Key Features of Lean
Production
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compared with Traditional Mass Production |
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Reduced Setup Cost and Times (for semi-versatile machinery such as
big stamping presses) - from months to hours thus making small-lot
production economically viable; achieved by organizing procedures, using
carts, and training workers to do their own setups,
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Small-Lot Production - allowing higher flexibility and pull
production (or just-in-time manufacturing)
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Employee Involvement and Empowerment
- organizing workers by
forming teams and giving them training and responsibility to do many
specialized tasks, for housekeeping, quality inspection, minor equipment
repair and rework; allowing also them time to meet to discuss problems and
find ways to improve the process
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Quality at the Source - total quality management (TQM)
and control; assigning workers, not inspectors, the responsibility to
discover a defect and to immediately fix it; if the defect cannot be
readily fixed, any worker can halt the entire line by pulling a cord
(called jidoka)
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Pull Production, or
Just-In-Time (JIT)
- the method wherein the quantity of work performed at each stage of the
process is dictated solely by the demand for materials from the immediate
next stage; thus reducing waste and lead times, and eliminating inventory
holding costs
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Continuous Equipment Maintenance - as pull production reduces
inventories, equipment breakdowns must also be reduced; thus empowered
operators are assigned primary responsibility for basic maintenance since
they are in the best position do detect signs of malfunction
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Multi- Skilled Workforce - as employees are empowered to do many
jobs, they must be provided with adequate training
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Supplier Involvement - the manufacturer treats its supplier as a
long-term partners; they often must be trained in ways to reduce setup
times, inventories, defects, machine breakdowns, etc. in order to enable
them to take responsibility for delivering the best possible
parts/services to the manufacturer in a timely manner.
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Strategy of Lean Production |
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The Seven Wastes To Be
Eliminated |
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Overpoduction and early production - producing over customer requirements, producing
unnecessary materials / products
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Waiting - time delays, idle time (time during which value is not
added to the product)
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Transportation - multiple handling, delay in materials handling,
unnecessary handling
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Inventory - holding or purchasing unnecessary raw materials, work
in process, and finished goods
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Motion - actions of people or equipment that do not add value to
the product
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Over-processing - unnecessary steps or work elements / procedures
(non added value work)
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Defective units - production of a part that is scrapped or requires
rework.
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Lean System Components and
Best Practices |
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Cultural awareness
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Workplace organization -
5S (sort - straighten - sweep - standardize - self-discipline) & visual control
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Standardized work
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Flexible operations
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Employee empowerment and
continuous improvement (see
Kaizen)
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Quick
changeover capability
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Total quality management & total productivity maintenance
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Error proofing
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Material
control
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Level production
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Traditional
Manufacturing |
Lean
Manufacturing |
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Scheduling |
Forecast - push |
Customer Order - pull |
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Production |
Stock |
Customer Order |
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Lead Time |
Long |
Short |
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Batch Size |
Large - Batch & Queue |
Small - Continuous Flow |
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Inspection |
Sampling - by
inspectors |
100% - at source by
workers |
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Layout |
Functional |
Product Flow |
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Empowerment |
Low |
High |
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Inventory Turns |
Low - <7 turns |
High - 10+ |
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Flexibility |
Low |
High |
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COGS |
High and Rising |
Lower and Decreasing |
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What is Lean Production?
Lean is about doing more with less: less time,
inventory, space people and money.
Lean
Manufacturing (also known as the Toyota Production System) is, in its most
basic form, the systematic elimination of waste - overproduction, waiting,
transportation, inventory, motion, over-processing, defective units -
and the implementation of the concepts of continuous flow and customer pull.
Five areas drive lean manufacturing/production:
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cost
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quality
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delivery
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safety, and
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morale.
Just as mass production is recognized as the production system of the 20th
century, lean production is viewed as the production system of the 21st
century.
Benefits of Lean Production
Establishment and mastering of a lean production
system would allow you to achieve the following benefits:
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Waste
reduction by 80%
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Production
cost reduction by 50%
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Manufacturing
cycle times decreased by 50%
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Labor
reduction by 50% while maintaining or increasing throughput
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Inventory reduction
by 80% while increasing customer service levels
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Capacity in current facilities
increase by 50%
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Higher quality
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Higher profits
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Higher system flexibility in reacting to
changes in requirements improved
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More strategic
focus
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Improved cash
flow through increasing shipping and billing frequencies
However, by continually focusing on waste
reduction, there are truly no end to the benefits that can be achieved.
Basic Elements of Lean Manufacturing
The basic elements are waste elimination,
continuous one piece workflow, and customer pull. When these elements are
focused in the areas of cost, quality and delivery, this forms the basis for
a lean production system.
The lean production concept was to a large
extent inspired by the
Kaizen - the Japanese strategy of continuous improvement. Employee
empowerment and promotion among them of a way of thinking oriented at
improving processes, imitation of customer relationships, fast
product development and manufacturing, and collaboration with suppliers are
the key strategies of leading lean companies.
Lean Production Overview
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Non-value
added activities or waste are
eliminated through continuous improvement efforts
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Focus on continuous
improvement of processes - rather than results - of the entire value chain
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The lean manufacturing
mindset: concept,
way of thinking - not techniques; culture - not the latest
management tool
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Continuous product flow is
achieved through physical rearrangement and system structure & control
mechanisms
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Single-piece flow / small lot
production: achieved through equipment set up time reduction; attention to
machine maintenance; and orderly, clean work place
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Pull reduction /
Just-in-time
inventory control
Applications
Lean techniques are applicable not only in
manufacturing, but also in service-oriented industry and service
environment. Every system contains waste, i.e. something that does not
provide value to your customer. Whether you are producing a product,
processing a material, or providing a service, there are elements which are
considered 'waste'. The techniques for analyzing systems, identifying and
reducing waste, and focusing on the customer are applicable in any system,
and in any industry.
Lean thinking may also be applied for
getting
rid of bureaucracy in your home office. To run your home office more
effectively and faster you may need just as little as 10% of its current
staff. Only executives who have a
direct involvement with finding, keeping, or growing customers as well
as key support staff - accountants, tax, legal and human resources people -
should stay. Others can be rehabilitated by sending to an operating unit.
Characteristics
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Integrated single piece continuous workflow
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Close integration of the whole
value chain from raw material to finished product through partnership
oriented relations with suppliers and distributors.
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Just-in-time processing: a
part moves to a production operation, is processed immediately, and moves
immediately to the next operation
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Short order-to-ship cycles times; small batch production capability that
is synchronized to shipping schedules
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Production is based on orders rather than forecasts; production planning
is driven by customer demand or "pull" and not to suit machine loading or
inflexible work flows on the shop floor.
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Minimal inventories at each stage of the production process
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Quick changeovers of machines
and equipment allow different products to be produced with one-piece flow
in small batches
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Layout is based on product flow
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Total quality control. Active involvement by workers in trouble shooting
and problem solving to improve quality and eliminate wastes.
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Defect prevention rather than inspection and rework by building quality in
the process and implementing real time quality feedback procedures.
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Team based work organizations with multi skilled operators empowered to
make decisions and improve operations with few indirect staff.
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