www.ies.ncsu.edu/lean
LEAN MANUFACTURING
PRINCIPLES
© NCSU IES LEAP Group Rev 3/04
www.ies.ncsu.edu/lean
The Connection

North Carolina State University
Teaching, Research, Extension and Engagement
 College of Engineering

Industrial Extension Service (IES)
www.ies.ncsu.edu/lean
Industrial Extension Service
 Lean Enterprise Advancement Program (LEAP)
 In-plant applications, manufacturing networks, public
training, Shingo Prize
 Advanced Performance and Standards (APS)
 FORUMS, QS, ISO, Six Sigma, Project management,
NC Awards for Excellence
 Environmental, Health and Safety (EHS)
 Training, technical assistance, needs assessment in
ISO, HAZWOPER, HAZMAT, ergonomics and industrial
hygiene
 Energy and Facilities Management
 Energy usage assessments
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Lean Enterprise Advancement Program
Mission Improve the quality, cost and delivery of
North Carolina manufacturing firms to
improve their competitiveness by
understanding and implementing lean
enterprise business systems based on
TPS model.
www.ies.ncsu.edu/lean
The LEAP mission is accomplished
through training
facilitation
manufacturing networks
lean assessments
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LEAN THINKING
Key Principles of Lean Thinking
 VALUE - what customers are willing to pay for
 VALUE STREAM - the steps that deliver value
 FLOW - organizing the Value Stream to be continuous
 PULL - responding to downstream customer demand
 PERFECTION - relentless continuous improvement
(culture)
--- Lean Thinking, Womack and Jones, 1996
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Defining Lean
Lean is:
“A systematic approach to identifying and eliminating
waste (non-value added activities) through continuous
improvement by flowing the product at the pull of the
customer in pursuit of perfection.”
The MEP Lean Network
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Lean Goals- TPS “True North”

Zero defects

100% value-add

Lot size of one

Pull of the customer
TSSC
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LEAN MANUFACTURING
Why Become Lean?
•PQCDSM
•Improve Customer Satisfaction
•Increase Sales and Profits
•Insure Long-term Health of Company
•Survival
•Create Sustainable Competitive Advantage
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Typical Results from Lean Conversions
Percentage of Benefits Achieved
0
25
50
75
100
Lead Time Reduction
Productivity Increase
WIP Reduction
Quality Improvement
Space Utilization
Flexibility
Skill Enhancement
Visual Management
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LEAN MANUFACTURING
Where has Lean been successfully
implemented?
•Manufacturing
Automotive
Industrial Products
Furniture
Textiles and Apparel
Printing and Packaging
Consumer Products
•Service Industries
•Military
•Healthcare
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Developing a Lean Factory
The Goal and Getting There from Here
•The Goal - Lean Throughout the Entire Enterprise
•Set Aggressive Improvement Goals
•Measurements of Existing Operations
•Recognize Current Problem Areas
•Apply the Lean Production System Concepts
•Commit to the Continuous Improvement Process
•Just do it!
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Value Added/Non-value Added

Value-added:
 ANY ACTIVITY THAT PHYSICALLY CHANGES THE
MATERIAL BEING WORKED ON (not rework/repair!)


Machining
Knitting

Drilling
Spreading/Cutting

Assembly
Dying

Painting
Sewing
Non-value added:
 ANY ACTIVITY THAT TAKES TIME, MATERIAL, OR
SPACE BUT DOES NOT PHYSICALLY CHANGE THE
MATERIAL

Sorting
Stacking

Counting
Checking
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Lean = Eliminating the waste
Value added
8 Wastes
5%





Non-value added



Overproduction
Excess
inventory
Defects
Non-value
added
processing
Waiting
Underutilized
people
Excess motion
Transportation
Typically 95% of Total Lead Time is Non-Value Added!!!
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Value Stream Mapping
A simple diagram of every step involved
in the material and information flows
needed to bring a product from order to
delivery.
Value stream maps can be drawn for
different points in time as a way to raise
consciousness of opportunities for
improvement.
- Lean Lexicon
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- Learning to See
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Lean Production System
Goals - highest quality, lowest cost, shortest lead times
Just-In-Time
•continuous flow
•takt time/pace
•pull system
•triggers
Heijunka
Involvement
Jidoka
•separate man &
machine work
•identify abnormal
conditions
•poka yoke
Standardized Work
Kaizen
Stable Manufacturing Process
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Toyota’s Philosophy
• Customer first
• People are the most valuable resource
• Kaizen (continuous improvement)
• Shop floor focus
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Lean Production System
Goals - highest quality, lowest cost, shortest lead times
Just-In-Time
•continuous flow
•takt time/pace
•pull system
•triggers
Heijunka
Involvement
Jidoka
•separate man &
machine work
•identify abnormal
conditions
•poka yoke
Standardized Work
Kaizen
Stable Manufacturing Process
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Stability
The Four Ms
Operations safely carried out with all task
organized in the best known sequence and
by using the most effective combination of
resources
•huMans
•Materials
•Methods
•Machines
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Stability
The 5S’s
•Sort
•Keep only what is needed in your area
•Stabilize
•A place for everything and everything in its place
•Shine
•Clean up the workplace
•Standardize
•Develop system (rules) to maintain what has been done
•Sustain
•Self discipline to maintain established procedures
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Stability
The 5S’s - Before
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Stability
The 5S’s
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Stability
The 5S’s
Courtesy of National Textiles
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Stability
Visual Controls
Visual Controls are simple signals that provide an
immediate understanding of a situation or condition. They
are efficient, self regulating, and worker managed.
Examples include:
• Pictures, diagrams
• Color coded dies, tools, pallets
• Lines on the floor to delineate storage areas, walk
ways, work areas, etc.
• Improved lighting
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Stability
Visual Controls
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Stability
Plant Layout
QC
Raw Stock
Shear
Stamp
Brake
Mill
Weld
Grind
QC
Screw
Machine
Lathe
Shipping
Receiving
Drill
Assembly
Finish
Parts Stock
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Stability
Cellular Layout
1
Lathe
2
Drill
27
Seconds
10
Pack
3
Mill
4
Mill
27
Seconds
9
Inspect
8
Drill
5
Inspect
27
Seconds
7
Test
Market Demand = 220,000 Units Per Year
Takt Time = 27 Seconds
6
Drill
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Stability
Cellular Layout
Courtesy of Duff-Norton, Charlotte, NC
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Stability
Total Productive Maintenance
Total Productive Maintenance (TPM) is a
series of methods to keep equipment running
The goals of the TPM process include:
•Develop people who are equipment-knowledgeable
•Create well-engineered equipment: building in safety and
quality
•Create an environment where enthusiasm and creativity
flourish
•Maximize equipment productivity and capacity as
measured by Overall Equipment Effectiveness (OEE)
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Stability
OEE = Availability × Performance Efficiency × Rate of Quality
Availability
Performance Efficiency
When or how often do you Does your equipment
lose total availability of
start and stop a lot?
your equipment?
Does your equipment run
How long are your setat 100% of its designed
ups?
speed?
Rate of Quality
Do you manufacture
quality products?
Are your processes
repeatable?
Does your equipment
break down frequently?
The Six Big Losses that downgrade Machine Effectiveness:
Related Losses
Related Losses
• Setup and
Adjustment
• Idling and Minor
Stoppages
• Breakdowns
• Reduced Speed
Related Losses
• Startup
• Defects and Rework
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Sample Daily Operator PM
Daily Operator PM

1. Check coolant level through clear Plexiglas

2. Check heat exchanger fans
(strings should be moving)

3. Check servo drive fans
(string should be moving)

4. Check heat exchanger air filter
(change when dark)

5. Check servo drive air filter
(change when dark)

6. Check way lube reservoir
(add when low)

7. Check main motor air filter
(change when dark)

8. Check main motor cooling fan
(string should move)

9. Check mist collector motor and air filter
(change when dark)
 10. Check bar feeder hydraulic motor air filter
 11. Check bar feeder hydraulic oil level
(add when low)
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Developing a Lean Factory
Summary – Stability in Manufacturing
Processes
•4Ms
•5S
•Visual Controls
•Plant Layout
•Total Productive Maintenance
www.ies.ncsu.edu/lean
Lean Production System
Goals - highest quality, lowest cost, shortest lead times
Just-In-Time
•continuous flow
•takt time/pace
•pull system
•triggers
Heijunka
Involvement
Jidoka
•separate man &
machine work
•identify abnormal
conditions
•poka yoke
Standardized Work
Kaizen
Stable Manufacturing Process
www.ies.ncsu.edu/lean
Just-in-Time
Pull System
•Pull System is a flexible and simple method of
controlling/balancing the flow of resources.
– Eliminating waste of handling, storage, expediting,
obsolescence, repair, rework, facilities, equipment,
excess inventory (work-in-process and finished).
•Pull System consists of:
– Production based on actual consumption
– Small Lots
– Low inventories
– Management by Sight
– Better Communication
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Just-in-Time
Pull System
• Kanban
- A signal to indicate when more parts are needed
(Order or Produce)
- Card, empty Bin, In Process Kanban (IPK) on plant floor
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Just-in-Time
Pull System
Courtesy of Ingersoll-Rand Co., Southern Pines, NC
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Just-in-Time
Supermarket Analogy
• A carton of milk is removed from shelf
•A stock person restocks the empty location,
but only brings what shelf can accommodate
•the supermarket combines visual control, pull system,
Kanban, 5S
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Just-in-Time
Quick Changeover (Set-up Reduction)
Single Minute Exchange of Dies (SMED)
•a series of techniques for changeovers of production
machinery in less than ten minutes (single digit
minutes)
Set-up Reduction Program Goals
•To achieve smaller lots
•To maintain consistent quality
•To minimize inventory
•To reduce lead times
•To address frustration of setup personnel
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Just-in-Time
Basic SMED Principles
 Identify
internal vs. external
changeover tasks
 Analyze
each task’s real
purpose and function
 Focus
on no/low cost
solutions
 Aim
to eliminate
changeover time
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Just-in-Time
Positioning Pins
Positioning Pins
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Just-in-Time
No/Low Cost Solution: One-Turn Methods
Pear-Shaped Hole Method
Tighten Here
Attach and
Remove
Here
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Just-in-Time
No/Low Cost Solution: One-Turn Methods
Speed Nut
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Just-in-Time
No/Low Cost Solution: One-Turn Methods
Wing Nut Method
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Just-in-Time
No/Low Cost Solution: One-Motion Methods
Cam Method
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Just-in-Time
Quick Changeover
Not quick: Must heat
molds and plates
before changeover
Quicker: Test stand
with hot plates to
pre-heat molds and
plates
Courtesy of Playtex Panama, Santo Domingo, DR
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Just-in-Time
Continuous Flow - Batch Size Reduction
•The best batch size is one - one piece flow, or
make one and move one!
•Benefits: Reduces WIP, lead time, cycle time,
etc. and improves quality
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Just-in-Time
• Batch & Queue Processing
Process
Process
Process
A
B
C
10 minutes
10 minutes
10 minutes
Lead Time: 30+ minutes for total order
21+ minutes for first piece
• Continuous Flow Processing
ProcessProcessProcess
A
B
C
12 min. for total order
3 min. for first part
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Just-in-Time
Takt Time = Demand Rate
Takt Time =
Work Time Available
Number of Units Sold
GOAL: Produce to Demand
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Developing a Lean Factory
Summary - Just-in-Time
•Pull Systems/Kanban
•Point Of Use Storage
•Quick Changeover/Setup Reduction
•Continuous Flow
•Takt Time
www.ies.ncsu.edu/lean
Lean Production System
Goals - highest quality, lowest cost, shortest lead times
Just-In-Time
•continuous flow
•takt time/pace
•pull system
•triggers
Heijunka
Involvement
Jidoka
•separate man &
machine work
•identify abnormal
conditions
•poka yoke
Standardized Work
Kaizen
Stable Manufacturing Process
www.ies.ncsu.edu/lean
Jidoka
Quality at the Source
•Source Inspection: Operators must be
certain that the product they are passing to the
next work station is of acceptable quality.
•Operators must be given the means to
perform inspection at the source, before they
pass it along.
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Jidoka
Quality at the Source
Source
Inspection at
Molding
Courtesy Sara Lee Intimate Apparel,
Villanueva, Honduras
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Jidoka
“Bull’s Eye”
for checking
package size
Courtesy of National Textiles
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Jidoka
Quality at the Source
•Samples or established standards are
visible tools that can be used in the cell for
such purposes
•Process Documentation defining quality
inspection requirements for each work station
may need to be developed
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Jidoka
Poka-Yoke (Mistake Proofing)
A Poka-yoke device is any mechanism that either
prevents a mistake from being made or makes the
mistake obvious at a glance.
Poka-yoke devices:
- perform well when corrective action involves trying to eliminate
oversights and omissions.
- can reduce the time and cost of informative inspection to near zero.
- used with source inspection, can ensure that proper operating
conditions exist prior to actual production.
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Jidoka
Poka-Yoke (Mistake Proofing)
Examples:
Fueling area of car has three mistakeproofing devices:
1.filling pipe insert keeps larger, leadedfuel nozzle from being inserted
2.gas cap tether does not allow the
motorist to drive off without the cap
3.gas cap is fitted with ratchet to signal
proper tightness and prevent overtightening.
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Jidoka
Poka-Yoke (Mistake Proofing)
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Jidoka
Andon
A visual management tool that highlights the status of operations in an area
at a single glance and that signals whenever an abnormality occurs.
An andon can indicate production status (for example, which machines are
operating), an abnormality (for example, machine downtime, a quality
problem, tooling faults, operator delays, and material shortages), and needed
actions, such as changeovers. An andon can also be used to display the status
of production in terms of the number of units planned versus actual output.
--- The Lean Lexicon
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Jidoka
Andon
Courtesy of Sara Lee Intimate Apparel
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Jidoka
Identifying Problems
“When I was asked to attend the general manager’s meeting the first time,
I was happy to attend because I thought I could say that there were
no problems in my department. And I said so when it was my turn
to report. Then, this General Manager from Toyota looked straight into
my eyes and said, ‘Steve, when you say you do not have a problem, that
is the problem.’”
At this moment, I realized that in order to succeed in this business,
I have to change my way of thinking totally.
--- From JIT Kakumei no Shogeki by Kiyoshi Suzaki, p. 14.
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Jidoka
Identifying Problems - Trystorming
Before
After
Courtesy of National Textiles
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Jidoka
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Developing a Lean Factory
Summary - Jidoka
•Quality at the Source
•Poka Yoke
•Andons
•Effective Problem Solving
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Lean Production System
Goals - highest quality, lowest cost, shortest lead times
Just-In-Time
•continuous flow
•takt time/pace
•pull system
•triggers
Heijunka
Involvement
Jidoka
•separate man &
machine work
•identify abnormal
conditions
•poka yoke
Standardized Work
Kaizen
Stable Manufacturing Process
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Standardization
Standardized Work
Establishing precise procedures for each operator’s work in a production
process, based on three elements:
1.
2.
3.
Takt time, which is the rate at which products must be made in a
process in order to meet customer demand.
The precise work sequence, in which an operator performs tasks within
takt time.
The standard inventory, including units in machines, required to keep
the process operating smoothly.
--- The Lean Lexicon
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Standardization
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Standardization
Standard Work Board
Courtesy of Ingersoll-Rand Co., Southern Pines, NC
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Standardization
Takt Time = 10 seconds
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Standardization
Heijunka
Leveling the type and quantity of
production over a fixed period of
time. This enables production to
efficiently meet customer
demands while avoiding batching
and results in minimum
inventories, capital costs,
manpower, and production lead
---The Lean Lexicon
time through the whole value
stream.
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Standardization
Heijunka Box
A tool used to level the
mix and volume of
production by distributing
kanban within a facility at
fixed intervals. Also
called a leveling box.
A load-leveling box has a
column of kanban slots
for each pitch interval, and
a row of kanban slots for
each product type.
---Learning to See
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Standardization
Paced Withdrawal
The practice of releasing
production instructions to
work areas and
withdrawing completed
product from work areas
at a fixed, frequent pace.
In this type of handling
system, a material
handler, or waterstrider,
performs a route through
a facility at precisely
determined time intervals.
---Learning to See
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Standardization
Courtesy of Duff-Norton, Charlotte, NC
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Standardization
Supermarket
The location where a
predetermined standard
inventory is kept to supply
downstream processes.
Supermarkets are
ordinarily located near the
supplying process to help
that process see customer
usage and requirements.
---Learning to See
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Standardization
Supermarket Pull System
Courtesy of Seamless Textiles, Humacao, PR
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Standardization
Kaizen
Continuous improvement of an entire
value stream or an individual process to
create more value with less waste.
There are two levels of kaizen (Rother and Shook 1999, p.8):
1. System or flow kaizen focusing on the overall
value stream (kaizen for management).
2. Process kaizen focusing on individual processes
(kaizen for work teams and team leaders).
- Lean Lexicon
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Developing a Lean Factory
Summary - Standardization
•Standardized Work
•Heijunka/Leveling
•Paced Withdrawal
•Supermarket
•Kaizen
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Lean Production System
Goals - highest quality, lowest cost, shortest lead times
Just-In-Time
•continuous flow
•takt time/pace
•pull system
•triggers
Heijunka
Involvement
Jidoka
•separate man &
machine work
•identify abnormal
conditions
•poka yoke
Standardized Work
Kaizen
Stable Manufacturing Process
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Involvement
Workplace Practices
•Teams
–with rotation of highly specified jobs.
•Cross trained and multi-skilled employees
–who can work many operations within a cell
and even operations in different cells
•Continuous improvement philosophy
•Process quality, not inspection
•Use of participatory decision making
–Quality Control Circles, team-based problem
solving, suggestion systems, etc.
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Keys To Success

Focus on the goal- eliminate waste!

Gather baseline information and
measure results

Get everyone involved

Keep it simple
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Reference Materials
• Lean Thinking by Jim Womack and Daniel Jones
• Lean Production Simplified by Pascal Dennis
•
Learning to See, Mike Rother, John Shook, The Lean
Enterprise Institute, Inc, 1998.
•
“Decoding the DNA of the Toyota Production System” by
Stephen Spear and H. Kent Bowen, Harvard Business
Review, September-October 1999, pp. 96-106
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Lean Enterprise
Advancement Program (LEAP)
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