Lean production systems

1. Prakash.g

2. • Lean production focuses on eliminating waste in processes (i.e. the
waste of work in progress and finished good inventories)
• Lean production is about expanding capacity by reducing costs and
shortening cycle times between order and ship date
• Lean is about understanding what is important to the customer
• Lean production is not about eliminating people
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4. Taiichi Ohno
(1912 †1990)
Shigeo Shingo
1909 †1990
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Founders of the Lean Production System (TPS)

5. Lean Production System
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• The production system developed by Toyota motor corporation to
provide best quality, lowest cost, and shortest lead time through the
eliminating of waste.
• The Lean production system was established on two concepts:
– JIDOKA: Automation with a human touch, means that when the problem
occurs, the equipment stops immediately, preventing defective product from
being produced.
– JUST-IN-TIME: In which each process produces only what is needed by the
next process in a continuous flow.

6. Toyota/Lean Production System house
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7. Just-In-Time Systems
What is JIT ?
JIT is a philosophy of continuous improvement in which
non-value-adding activities (or wastes) are identified and removed for the purposes
of:
 Reducing Cost
 Improving Quality
 Improving Performance
 Improving Delivery
 Adding Flexibility
 Increase innovativeness
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8.  Producing only what is needed, when it is needed
(not early, not late; not less, not more)
 Achieving high volume production using minimal
inventories
 An integrated but simplified system
 JIT’s mandate:
Elimination of all waste in production effort
Just-In-Time Systems
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9.  Attacks waste (anything not adding value to the product)
 Achieves streamlined production by reducing inventory
 Exposes problems and bottlenecks caused by variability
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What Does Just-in-Time Do?

10. Waste (“muda” in Japanese) is ‘anything other than the minimum
amount of equipment, materials, parts, space, and worker’s time,
which are absolutely essential to add value to the product.’
— Shoichiro Toyoda
Founder, Toyota
© 1995 Corel Corp.
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What is Waste?

11. Sources of Waste
 Overproduction
 Waiting
 Unnecessary transportation
 Inventory
 Inefficient work methods
 Inefficient processing
 Unnecessary motions
 Product defects
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12. Waste in Operations (1 of 3)
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13. Waste in Operations (2 of 3)
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14. Waste in Operations (3 of 3)
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15. Main Components of JIT
 Pull System
 Continuous Flow Processing
 Takt Time
 Flexible Workforce (Shojinka)
 3 M’s
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Just-In-Time

16. The Pull System
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Pull System is a flexible and simple method of controlling/balancing the
flow of resources.
Produce only when your customer demands the product in the required
quantity.
Run the production according to this demand
Pull System consists of:
– Production based on actual consumption
– Small Lots
– Low inventories
– Management by Sight
– Better Communication

17. The Pull & Push System
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18. Continuous/One-Piece Flow
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Producing and moving one item at a time (or a small and consistent batch of
items) through a series of processing steps as continuously as possible, with
each step making just what is requested by the next step.
It is also called the one-piece flow, single-piece flow, and make one & move
one.

19. Continuous/One-Piece Flow
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20. Takt time is the pace of production required to meet customer demand.
Since takt time is defined by the customer, it becomes a very important number
in a lean environment.
How:
Only 2 variables are used to calculate Takt time: Available Time &
Customer Demand (schedule):
Available time is total shift time minus meal and scheduled break times
TAKT Time
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21. TAKT Time
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22. Flexible Workforce (Shojinka):
Flexible workforce or shojinka means to alter (decrease or increase)
the number of operators within a shop, to equip with demand changes.
Continually optimizing the number of workers in a work center to
meet the type and volume of demand imposed on the work center. Creating
Flow and Eliminating Waste.
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Flexible Workforce (Shojinka)

23. Multi-machine Handling
Type of Part
A B C D
Machine 1
Machine 2
Machine 3
Machine 4
One person handles one process, four machines
Unfinished Parts
Finished Products
Flexible Workforce (Shojinka)
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24. Flexible Workforce (Shojinka)
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Multi-process Handling
Type of Part
A B C D
Machine 1
Machine 2
Machine 3
Machine 4
One person handles four processes, four machines

25. 3 M’s
MUDA = Non-Value Added
MURA = Overburden
MURI = Unevenness
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3 M’s

26. 1 TON
4 ton
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Capacity : 4 tons
Muda . Mura . Muri
12 TONS

27. X 2 = MURI (OVERBURDEN)
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X 6 = MUDA (NON-VALUE ADDED)
= MURA (UNEVENNESS)
Muda . Mura . Muri

28. The most efficient way to deliver 12 tons of good to the destination is:
NO MURI (OVERBURDEN)
X 3 = NO MUDA (NO WASTAGE)
NO MURA (NO UNEVENNESS)
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Muda . Mura . Muri

29. Kanban
What is Kanban?
• Card system that controls production & inventory
•Communicates demand for work or materials from the preceding station
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30. Kanban is one of the Lean tools designed to reduce the idle time in a production
process. The main idea behind the Kanban system is to deliver what the process
needs exactly when it needs it.
In Japanese, the word “Kan” means “card" and "ban" means “signal," so Kanban
refers to signal cards. Lean uses visual cards as a signaling system that triggers an
action to supply the process with its needs either from an external supplier or from
a warehouse.
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Kanban

31. Kanban
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32.  Reduction of eliminating non-value added activities
 Reduction of floor space and warehouse space per unit of output
 Reduction of setup time and schedule delays as the factory becomes a
continuous production process.
 Reduction of waste and rework by detecting errors at the source.
 Better utilization of machines and facilities.
 Better integration of and communication between functions such as
marketing, purchasing, design, and production.
 Quality control built into the process.
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Benefits of JIT

33. Jidoka - Automation
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What is Jidoka/Automation?
Providing machines and operators the ability to detect when an abnormal
condition has occurred and immediately stop work. This enables operations
to build in quality at each process and to separate men and machines for
more efficient work.
Jidoka highlights the causes of problems because work stops immediately
when a problem first occurs. This leads to improvements in the processes
that build in quality by eliminating the root causes of defects.

34. Jidoka - Automation
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35. Jidoka - Automation
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36. Jidoka Steps
1. Detect the abnormality.
2. Stop.
3. Fix or correct the immediate condition.
4. Investigate the root cause and install a countermeasure.
Why Jidoka?
• Increase quality
• Lower costs
• Improve customer service
• Reduce lead time
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Jidoka - Automation

37. Prevention Techniques
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• Poka Yoke - Mistake-Proofing
– Visual control of quality
– Prevents defects from happening
• Andons
– Commonly lights to signal production line status
• Red: line stopped
• Yellow: call for help
• Green: all normal
– Andon signals require immediate attention

38. Poka Yoke – Mistake Proofing
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What is it for?
• To eliminate the possibility or opportunity for passing on errors or
making mistakes in a process.
Where could we use it?
• In the development or improvement of any process.
• When you want to make wrong actions impossible or more difficult to do.
• When there is a need to make it possible to reverse actions
• When you need to make it easier to discover that errors occur.

39. Poka Yoke - Examples
Spellcheck:
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40. Andon
Andon is an information tool which provides instant, visible and audible
warning to the Operations team that there is a abnormality within that
area.
When the equipment shuts down because of a quality problem, flags or light,
usually with accompanying music, signal that help is needed to solve the
problem.
This signaling system is called the andon system.
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41. Visual Management Andon Lamp
• Red - line stoppage
• Yellow - call for help
• Green - normal operation
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42. Benefits of Lean Production
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Lean will improve:
Quality performance, fewer defects and rework.
Fewer Machine and Process Breakdowns.
Lower levels of Inventory.
Greater levels of Stock Turnover.
Less Space Required.
Higher efficiencies, more output per man hour.
Improved delivery performance.
Faster Development.
Greater Customer Satisfaction.
HIGHER PROFITS!
INCREASED BUSINESS!

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