2. Intro-To-Lean
Lean Manufacturing Definition
Lean has been defined in many different ways.
“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.”
By The MEP Lean Network
4. Intro-To-Lean
Lean manufacturing is a
philosophy
In 1990 James Womack, Daniel T. Jones, and
Daniel Roos wrote a book called “The Machine
That Changed the World: The Story of Lean
Production-- Toyota's Secret Weapon in the Global Car
Wars That Is Now Revolutionizing World Industry”
In this book, Womack introduced the Toyota
Production System to American.
What was new was a phrase–
"Lean Manufacturing."
5. How to Increase Profit?
Intro-To-Lean
Profit
Cost
Profit
Cost
Profit
Cost
6. Intro-To-Lean
Muda (Waste)
Taiichi Ohno (1912-1990), the Toyota executive who was the most
ferocious foe of waste human history has produced, identified the
first seven types of muda in manufacturing system:
• Storage
• Transportation
• Waiting
• Motion
• Process
• Defects
• Over-production
Muda is everywhere.
12. Intro-To-Lean
Kanban Operation
WK(2)
PK(1) PK(i+1)
PK(2) PK(N)
WK(1) WK(N)
WK(i+1)
WK(i) PK(i)
RM FG
Kanban Stage
1
Kanban Stage
i
Station
1
Station
2
Station
i
Station
i+1
Station
N+1
Figure 3.3. A kanban stage formed by two adjacent stations.
From stage i-1 To stage i+1
1
2
i
3
Kanban Stage
i
i +1
WK
PK
4
K
K-1
5
16. Intro-To-Lean
Which to Choose — MRP
(ERP), or Kanban?
Where MRP (ERP) works best:
MRP is by its very nature a forward-looking
system.
MRP can be very effective in an environment with
a great deal of variability.
MRP is recognized an engine to drive an integrated
enterprise-wide information system. Purchasing
and logistics activities were similarly being
integrated with fundamental internal materials
management principles into an enterprise-wide
approach.
17. Intro-To-Lean
MRP or Lean Manufacturing?
MRP is a predictive system. It does not reflect to
customer’s demand (easy to get overproduction).
A company takes MRP suggestions and acts on them
without too much review is very risky.
MRP won’t fully support the cost-cutting.
MRP needs lots of data for production management.
MRP generates high overhead.
MRP builds high work-in-process.
MRP’s lead times are fixed.
MRP creates potential quality hazard.
Where MRP is not as effective.
18. Intro-To-Lean
Which to Choose — MRP
(ERP), or Kanban?
Where Kanban works best.
Kanban is a very reactive system. Very little is planned
ahead. Instead, Kanban causes replacement of material used in a
totally reactive mode. Kanban works best in a highly stable and
predictable environment.
Where it is not as effective.
Kanban can quickly fail in a highly volatile environment
because of the reactive nature of the system. Volatility in
customer demand, processing problems, and extensive changes
in product designs make it very difficult for a Kanban system to
work effectively.
19. Intro-To-Lean
Which to Choose — MRP
(ERP), or Kanban?
Kanban and MRP Combination
The combination of these two systems is becoming quite
common. An MRP system is used for advanced planning,
including long lead-time purchased materials, adding resources,
and implementing product design changes. Once the MRP has the
materials and resources “lined up,” however, Kanban is used as
an execution system, bringing with the characteristics of rapid
response to customer order and reduced inventory levels
throughout the process.
Hybrid Systems
20. Intro-To-Lean
The Objections to Lean
How should you deal with these objections to lean?
•“It is very hard to deal with raw material suppliers
if we fully depend on customer order.”
•“It takes too much discipline.”
•“It takes too long to implement.”
•“My process is too complex; I have to deal with
too many uncontrollable variables, like late supplier
shipments, sick people, etc.”
•“My process requires a large batch size.”
•“It doesn’t make sense in my industry.”
•“It’s unclear to me how lean will work with my
MRP system.”
21. Intro-To-Lean
Lean and Green
The environmental impacts due to
production and waste generation
have made its way into every day
society.
Consumers are becoming more
environmentally conscious.
With the Earth’s limited resources,
companies are more conscious of
their carbon footprint, and there has
been a movement to create more
environmentally friendly decisions.
Green engineering is the systems-level approach to product and
process design where environmental attributes are treated as primary
objectives or opportunities rather than simple constraints.
22. Intro-To-Lean
lean manufacturing is a link
to green engineering
Lean manufacturing is the business model and collection of tactical
methods that emphasize eliminating non-value- added activities
(waste) while delivering quality products at lowest cost with greater
efficiency. In conjunction, six goals of green engineering are:
1. Select low environmental impact materials.
2. Avoid toxic or hazardous materials.
3. Choose cleaner production processes.
4. Maximize energy and water efficiencies.
5. Design for waste minimization.
6. Design for recyclability and reuse of material.
23. Intro-To-Lean
lean manufacturing is a link
to green engineering
Population grows
Wastes increase
Fossil fuels are diminishing and there is nothing replenishing them.
Consumers are becoming more aware of the environment and
prefer environmentally friendly companies.
Being lean and green is so important now to reduce the
consumption of natural resources and the CO2 concentration
in the Earth’s atmosphere.
The only real difference between lean and green manufacturing is
that green actually designs the product or process with the
environment as a constraint while lean creates a process with the
view of the environment as a valuable resource and not a
constraint.
24. Intro-To-Lean
Key Steps in Transforming
a Company to the Lean
Approach
1. Establish a steering team—conduct strategic planning session
2. Train the steering team and the model line team in the
disciplines of lean
3. Perform PQR (product-quantity-routing) analysis
4. Identify value streams—select a value stream
5. Calculate model line takt time
6. Value stream map the model line—assemble current state map
7. Balance the line—assign standard work
8. Establish standard WIP (inventory levels)
9. Test the system (virtual cell)—document results
10. Setup reduction event
25. Intro-To-Lean
Key Steps in Transforming
a Company to the Lean
Approach
11. Conduct 5S event—apply TPM techniques
12. Establish visual signals—reduce paperwork
13. Explore alternative flow patterns
14. Develop block layout
15. Develop detailed layout
16. Execute move
17. Select next value stream and repeat
Gary Conner, President of Lean Enterprise Training, Newport, OR, Road Map to
Lean for the Smaller Shop, Society of Manufacturing Engineers, Lean
Manufacturing 2007, Supplement to Manufacturing Engineering, 2007. pp. 27-29.
26. References
• Society of Manufacturing Engineers, Lean Manufacturing 2007,
Supplement to Manufacturing Engineering, 2007.
• Society of Manufacturing Engineers, Lean Manufacturing 2008,
Supplement to Manufacturing Engineering, 2008.
• Garrett Brown and Dara O’Rourke, “Lean Manufacturing Comes to
China: A Case Study of its Impact on Workplace Health and Safety,”
International Journal of Occupational and Environmental Health (IJOEH),
13(3), JUL/SEP 2007.
• Challenges in Applying Lean Manufacturing in China, McKinsey
Quarterly, 2006 Special Edition available at Jackson Library. Friday,
October 12, 2007 | Posted by Simone Yu in International
Intro-To-Lean
