Transcript Lean Operations - Georgia Institute of Technology

Lean Operations
“Eliminate Waste
Through
Continuous Improvement”
A Little History!
 Benjamin Franklin
 Poor Richard’s Almanac: He that idly loses 5s.
[shillings] worth of time, loses 5s., and might as
prudently throw 5s. into the river. He that loses
5s. not only loses that sum, but all the other
advantages that might be made by turning it in
dealing, which, by the time a young man
becomes old, amounts to a comfortable bag of
money."
A Little History!
 Gilbreth
 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.
A Little History!
 Ford: Eliminate Waste
 "I believe that the average farmer puts to a really
useful purpose only about 5 %. of the energy he
expends. … Not only is everything done by hand,
but seldom is a thought given to a logical
arrangement. A farmer doing his chores will walk
up and down a rickety ladder a dozen times. He
will carry water for years instead of putting in a
few lengths of pipe. His whole idea, when there
is extra work to do, is to hire extra men. He
thinks of putting money into improvements as an
expense. … It is waste motion— waste effort—
that makes farm prices high and profits low."
A Little History!
 Ford: Design for manufacturing
 Start with an article that suits and then study to
find some way of eliminating the entirely useless
parts. This applies to everything— a shoe, a
dress, a house, a piece of machinery, a railroad, a
steamship, an airplane. As we cut out useless
parts and simplify necessary ones, we also cut
down the cost of making. ...But also it is to be
remembered that all the parts are designed so that
they can be most easily made."
A Little History!
 Ohno – put ideas into practice systematically
 “When bombarded with questions from our
group on what inspired his thinking, Ohno just
laughed and said he learned it all from Henry
Ford's book."
Waste: Classification
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Waste from overproduction
Inventory waste
Waste from waiting time
Transportation waste
Processing waste
Waste of motion
Waste from product defects
TPS: Toyota Production System
 A system that continually searches for and
eliminates waste throughout the value chain.
 Views every enterprise activity as an operation and
applies its waste reduction concepts to each
activity - from Customers to the Board of Directors
to Support Staff to Production Plants to Suppliers.
TPS: Toyota Production System
Reducing Waste: Quality at Source
 Failsafe design (Poka-Yoke)
 Stopping work immediately when problem
occurs (Jidoka)
 Line-stopping empowerment (Andon)
Poka-Yoke
Poka-Yoke
 Poka-yoke page:
http://csob.berry.edu/faculty/jgrout/pokayoke.shtml
Jidoka
Andon
Reducing Waste: Quality at Source
Defects found
at:
Impact to the
Company:
Current
Process
· Very
Minor
Next
Process
· Minor
Delay
End of
Line
Final
Inspection
End User
· Rework
· Significant · Warranty
Rework
Costs
· Rescheduling
of work
· Delay in
· Administrative
Delivery
Costs
· Additional · Reputation
Inspection · Loss of
Market Share
Reducing Waste: Increase Problem Visibility
Inventory
Supply Fluctuations
Missed Due Dates
Excessive Paperwork
Scrap & Rework
Machine Downtime
Reducing Waste: Push versus Pull System
Raw
Material
Supplier
Final
Assembly
Customer
FGI
PUSH
Raw
Material
Supplier
Final
Assembly
Customer
FGI
PULL
Information Flow
Material Flow
TPS System uses Kanbans
Reducing Waste: From Functional Layout…
Production
Control
Production
Control
Production
Control
Roof
Cut
Roof
Cut
Roof
Cut
Base
Cut
Base
Cut
Base
Cut
FA
FA
FA
Base
Assy
Base
Assy
Base
Assy
QC
QC
QC
...to Cell Layout
Production
Control
Production
Control
Production
Control
Roof
Cut
Base
Cut
Roof
Cut
Base
Cut
Roof
Cut
Base
Cut
FA
Base
Assy
FA
Base
Assy
FA
Base
Assy
Reducing Waste: Cut Batch Sizes
Example Process:
0
1
2
3
4
8
A
B
C
D
1 min/job
1 min/job
1 min/job
1 min/job
Batch Mfg. (Lot Size = 4)
4
A
B
4
C
D
0
1
2
3
4
8
4
16
Time
4
16
Time
Flow Mfg. (Lot Size = 1)
1
1
A
B
1
C
1
D
Synchronize: Heijunka
Mixed, Level/Balanced Production
Batch Production Schedule
(AAAABBBB...)
Apr/12.........15..................30
Mixed Production Schedule
(ABAB...)
Apr/12..........15...................30
Products
A
B
FGI
FGI
time
time
Continuous Improvement: Kaizen
 Increase visibility of waste
 Standardize work
 Targeted improvements
 Active worker involvement
 Supplier involvement
 Time for experimentation
 Exploratory stress
TPS: Toyota Production System
A system that continually searches for and
eliminates waste throughout the value chain.
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




Poka-Yoke
Jidoka
Andon
Kanban
Heijunka
Kaizen
Management By Stress:
Does “S” in TPS Stand for Stress (1)?
 “Empower employees”  Employees responsible for
errors.
 “Drive out waste”  No slack in the human system.
 “Kaizen”  Improvements discovered by workers are
co-opted by management.
 “Workers design their jobs”  Workers do industrial
engineering jobs without the pay.
Management By Stress:
Does “S” in TPS Stand for Stress (2)?
 “Reduce indirect labor”  Make workers do
management’s job.
 “Reduced buffers”  More stress and less room for error
or fatigue.
 “Respect for workers”  As long as workers define their
personal goals as satisfying management’s agenda…
 “Productivity enhancements are dramatic”  Workers
work real hard, with little spare time.
If You’re Curious to know more..
 Lean Blog: http://kanban.blogspot.com/
 Books:
 Ohno, Taiichi (1988), Toyota Production System: Beyond
Large-Scale Production, Productivity Press.
 Womack, James P., Jones, Daniel T., and Roos, Daniel
(1991), The Machine That Changed the World: The Story
of Lean Production, Harper Perennial
 Womack, James P. and Jones, Daniel T. (1998), Lean
Thinking Free Press.
 Levinson, William A. (2002), Henry Ford's Lean Vision:
Enduring Principles from the First Ford Motor Plant,
Productivity Press
 Ford, Henry and Crowther, Samuel (2003), My Life and
Work, Kessinger Press.