Lean Operations
“Eliminate WasteThrough
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
Waste from overproduction Inventory waste Waste from waiting time Transportation waste Processing waste Waste of motion Waste from product defects
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)
TPS: Toyota Production System
Poka-Yoke
Poka-Yoke
Poka-yoke page: http://csob.berry.edu/faculty/jgrout/pokayoke.shtml
Jidoka
Andon
Defects found at:
Current Process
Next Process
End of Line
Final Inspection
End User
Impact to the Company:
· VeryMinor
· MinorDelay
· Rework
· Reschedulingof work
· SignificantRework
· Delay inDelivery
· AdditionalInspection
· WarrantyCosts
· AdministrativeCosts
· Reputation
· Loss ofMarket Share
Reducing Waste: Quality at Source
Reducing Waste: Increase Problem Visibility
Missed Due Dates
Scrap & Rework Machine Downtime
Supply Fluctuations
Excessive Paperwork
Inventory
Material Flow
Information Flow
FGI
CustomerRaw
MaterialSupplier
FinalAssembly
PUSH
FGI
CustomerRaw
MaterialSupplier
FinalAssembly
PULL
TPS System uses Kanbans
Reducing Waste: Push versus Pull System
ProductionControl
ProductionControl
ProductionControl
RoofCut
RoofCut
RoofCut
BaseCut
BaseCut
BaseCut
FABaseAssy
FA FABaseAssy
BaseAssy
QC QC QC
Reducing Waste: From Functional Layout…
ProductionControl
FA
BaseCut
RoofCut
BaseAssy
ProductionControl
FA
BaseCut
RoofCut
BaseAssy
ProductionControl
FA
BaseCut
RoofCut
BaseAssy
...to Cell Layout
Batch Mfg. (Lot Size = 4) Flow Mfg. (Lot Size = 1)01234
8
16
Time
Example Process: A B C D
1 min/job 1 min/job 1 min/job 1 min/job
A B C D
4
4
4
4
A B C D
Time
11
11
01234
8
16
Reducing Waste: Cut Batch Sizes
Batch Production Schedule Mixed Production Schedule
(AAAABBBB...) (ABAB...)
Apr/12.........15..................30 Apr/12..........15...................30
Products
A
B
time
FGI
time
FGI
Synchronize: HeijunkaMixed, Level/Balanced Production
Increase visibility of waste Standardize work Targeted improvements
Active worker involvement Supplier involvement Time for experimentation
Exploratory stress
Continuous Improvement: Kaizen
A system that continually searches for and eliminates waste throughout the value chain. Poka-Yoke Jidoka Andon Kanban Heijunka Kaizen
TPS: Toyota Production System
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.
“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.
Management By Stress: Does “S” in TPS Stand for Stress (2)?
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.