1. business and industrial
2. manufacturing

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JUST--IN
JUST
IN--TIME MANUFACTURING
• Overview of Toyota Production System
• Three Ms: Muda,
Muda, Mura and Muri
• Pull vs. Push System
• Kanban and its types
• Just
Just--in
in--time purchasing
• Total quality control and JIT
• Barriers to Implementation of JIT
• Benefits of JIT
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Overview of Toyota Production System
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Objectives:
• Reducing costs by eliminating all kinds of costs
• Making it easier to achieve and assure product quality
• Attempting to create work sites that respond quickly to change
• Organizing work sites based on human dignity, mutual trust
and support
Components:
• Process job design and job standardization
• Economic lot sizes and accelerated setup times
• Just
Just--inin-time production
• Autonomation
• Kanban
• Jikoda
Jikoda--Andon
• Yo
Yo--i-don
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Brief History of Manufacturing
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In Japan…
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Lean production wa
was
s developed in Japan Mr. Toyoda and Mr.
Ohno of Toyota after analyzing mass production after II. World War.
There were some factors forced Toyada and Ohno to develop this
system.
Japan Market was small and it was demanding extensities types of
car models such as:
o
Luxury cars for politicians,
o
Small trucks for farmers,
o
Lorries for transporters
Japanese
Japan
ese economy collapsed after II. World War and needed capital
and foreign money, therefore buying a western latest technology
was almost impossible.
There were no immigrated workers at Japan who could work under
standard working conditions.
There were very powerful car companies such as GM and Ford
outside Japan and they were ready to defend
defend their market.
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Main Characteristics
haracteristics of Lean Manufacturing
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• Involving the human factor in the production so that
everyone has a big responsibility about production even
they can stop the production by the help a cable with his
initiative and thus every employee add something to the
car,
• Cooperation with the supplier and trusting each other in
order to produce exactly the needed product in a short
time and also reduce the holding cost,
• Causing that everybody beginning from the newcomers
knows
know
s something about each department in the
company.
• Improving quality by examining each mistake at the point
where it happens and making everyone aware of it so
that it won’t happen again.
again.
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Brief History of Lean Manufacturing
Manufacturing::
Evolution of paradigms
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3
Terms of TPS
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Autonomation: Manual or automatic stopping of
production, if a defective part is produced.
Kanban: System of cards used to control WIP
(work--in
(work
in--process), production and inventory
control
Jikoda: Production problem warning system
Andon: Yellow and red lights for warning
YoYo-i-don: Coordinated approach to simultaneous
production of parts, subassemblies for the next
stage in assembly.
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Three Ms: Muda, Mura and Muri
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MUDA: Waste
Waste,, work that does not add any value to the
product
KAIZEN: The job attitude of looking for muda and finding
ways to eliminate it
Types of Muda:
• Muda for correction
• Muda of overproduction
• Muda for processing
• Muda in conveyance
• Muda for inventory
• Muda of motion
• Muda for waiting
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4
Mura & Muri
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MURA: Unevenness,
Unevenness, unbalanced workloads on
machines
Result: Excess capacity allocation and increased
cost
MURI: Overburden,
Overburden, stretching beyond capacity limits
Result: Safety and quality problems due to
excessive overload on people, facilities, equipment
and all sorts of tools.
Market share and profitability = F(Unit Cost, Quality,
Lead Time)
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Push vs. Pull System
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PUSH System:
• MRP based production planning and control system
• MPS of end products is transformed into part
requirements
• The work orders are launched to make/buy parts in lots
• Lot sizes are large and lead times are long.
PULL System:
• MPS is only used to give a broad outline of the
requirements
• MPS is used to decide approximate resource
requirements of WS (work stations)
• MPS is NOT used to decide production rate of WS
• Kanban is used to trigger production at every stage
• Short term scheduling and production
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Push (Top) vs. Pull (Bottom) System
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JIT: JustJust-In
In--Time (Production)
Production)
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Goals of JIT:
• Receive supplies just in time to be used
• Produce parts just in time to be made into subassemblies
• Produce subassemblies just in time to be assembled into
finished products
• Produce and deliver finished products just in time to be sold
Traditional systems: Push systems
JIT systems:
Pull systems
Advantages of JIT:
• Low inventory carrying costs
• Fast detection of defects in before or during production and low
scrap loss
• Reduced inspection and rework of parts
• High quality parts at low cost.
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Kanban and Its Types
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KANBAN: Visible record
>> Production card and conveyance (move) card
>> Recently: bar coded plastic tags or other devices
Withdrawal (conveyance) Kanban:
Kanban:
Passes the authorization for movement of parts
from one work center to another
Production Kanban:
Releases an order to the preceding process to
build parts equal to the lot size specified on the
card.
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Withdrawal
Kanban
Production
Kanban
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Flow Sequences in Kanban Production System
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Setup and Holding Costs vs. Quantity
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Flow of Signal Kanbans
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Just--in
Just
in--time purchasing
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• Purchase lot size:
size: small quantities; frequent deliveries
• Supplier selection:
selection: Crucial; fewer (ideally one) nearby supplier
• Supplier evaluation:
evaluation: Criteria; quality, delivery performance
and price
• Receiving Inspection:
Inspection: executed at the suppliers’ plant
• Negotiating and bidding process:
process: Emphasis is NOT on the
lowest price; but on quality & long term relationship
• Mode of transportation:
transportation: Concern on both inbound and
outbound freight and on time delivery
• Product specifications:
specifications: Emphasis is on product performance
rather than specifications
• Paperwork
Paperwork:: Reduced time taking paperwork; increased
electronic communication
• Packaging
Packaging:: exact amount of parts in smaller containers
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Barriers to Implementation of JIT
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• Frequent changes in production planning
• Inaccurate forecasting procedures
resulting in underunder- or overover-forecasting of
demand
• Equipment failures creating capacity
problems
• Employee turnover, absenteeism etc.
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Benefits of JIT
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Increased productivity
Better quality
Reduced lead times
Less scrap and rework
Less WIP (work in process)
Higher worker motivation and increased
teamwork
• Saved space
• Increased worker and equipment efficiency
•
•
•
•
•
•
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Functional areas benefiting from
JIT manufacturing
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• Manufacturing
• Manufacturing engineering
• Purchasing
• Sales and marketing
• Accounting
• Quality control
• Assembly
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Supply Chain Management
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• OEM’s
• Suppliers
* 1st tier suppliers (design partners and/or part
manufacturers, trade companies etc.)
* 2nd tier suppliers (manufacturers and trade
companies)
• Supply chain management companies/agencies
companies/agencies
• Logistics companies
• Transportation companies
• Customs, handling and storage companies
• Financial institutions
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