3. Push System
Every worker maximizes own output, making
as many products as possible
Pros and cons:
Focuses on keeping individual operators and
workstations busy rather than efficient use of
materials
Volumes of defective work may be produced
Throughput time will increase as work-in-process
increases (Little’s Law)
Line bottlenecks and inventories of unfinished
products will occur
Hard to respond to special orders and order
changes due to long throughput time
4. Pull System
Production line is controlled by the last
operation, Kanban cards control WIP
Pros and cons
Controls maximum WIP and eliminates WIP
accumulating at bottlenecks
Keeps materials busy, not operators. Operators
work only when there is a signal to produce.
If a problem arises, there is no slack in the system
Throughput time and WIP are decreased, faster
reaction to defects and less opportunity to create
defects
5. 5
• Management philosophy
• “Pull” system though the plant
WHAT IT IS
• Employee participation
• Industrial engineering/basics
• Continuing improvement
• Total quality control
• Small lot sizes
WHAT IT REQUIRES
• Attacks waste
• Exposes problems and bottlenecks
• Achieves streamlined production
WHAT IT DOES
• Stable environment
WHAT IT ASSUMES
Features of Lean Production
Kaizen
6. 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."
7. 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."
8. 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
9. Elimination of Waste
Complexity
Labor
Overproduction
Space
Energy
Defects
Muda
Materials
Inventory
Time
Transportation
Acronym – CLOSED MITT
10. 10
1. 5S
2. Group technology
3. Quality at the source
4. JIT production
5. Kanban production control system
6. Minimized setup times
7. Uniform plant loading
8. Focused factory networks
Elimination of Waste
11. Minimizing Waste – 5S
“Good factories develop beginning with the 5S’s.
Bad factories fall apart beginning with the 5 S’s.”
- Hirouki Hirano
Japanese Translation English
Seiri Proper arrangement Sort
Seiton Orderliness Simplify
Seiso Cleanliness Sweep
Seiketsu Cleanup Standardize
Shitsuke Discipline Sustain
12. Minimizing Waste – 5S
A place for everything and everything in its place
Not just a housekeeping issue
Critical foundation for
Setup reduction
Pull systems
Maintenance
Inventory management
13. Using Departmental Specialization (Job Shop) for plant layout
can cause a lot of unnecessary material movement
Saw Saw
Lathe Press
Press
Grinder
Lathe
Lathe
Saw
Press
Heat Treat
Grinder
Note how the flow lines are going back and forth
Minimizing Waste: Group Technology
15. Minimizing Waste: JIT
Only produce what’s needed
The opposite of “Just In Case” philosophy
Ideal lot size is one
Minimize transit time
Frequent small deliveries
Pro’s
•Minimal inventory
•Less space
•More visual
•Easier to spot quality issues
Con’s
•Requires discipline
•Requires good problem solving
•Suppliers or warehouses must be close
•Requires high quality
???
17. Minimizing Waste – Quality at the
Source
“Do it right the first time”
Call for help
Immediately stop the process and correct it vs.
passing it on to inspection or repair
Andon
19. Minimizing Waste – Kanban
Signaling device to control flow of material
•Cards
•Empty containers
•Lights
•Colored golf balls
•Etc
20. Minimizing Waste – Setup Times
Long setup times drive:
Long production runs
Large lots
Long lead times
JIT requires small lots and minimum kanbans
Setup reduction
Focused efforts
Problem solving
Flexible equipment
21. 21
Not uniform Jan. Units Feb. Units Mar. Units Total
1,200 3,500 4,300 9,000
Uniform Jan. Units Feb. Units Mar. Units Total
3,000 3,000 3,000 9,000
Suppose we operate a production plant that produces a single
product. The schedule of production for this product could be
accomplished using either of the two plant loading schedules below.
How does the uniform loading help save labor costs?
or
Minimizing Waste – Plant Loading
Heijunka
22. Coordination
System Integration
These are small specialized
plants that limit the range of
products produced
(sometimes only one type of
product for an entire facility)
Minimizing Waste –
Focused Factory
Networks
23. Level payrolls
Cooperative employee unions
Subcontractor networks
Bottom-up management style
Quality circles (Small Group Problem Solving)
TPS – Respect for People
Keiretsu
24. 1. All work shall be highly specified as to content, sequence,
timing, and outcome
2. Every customer-supplier connection must be direct, and
there must be an unambiguous yes-or-no way to send
requests and receive responses
3. The pathway for every product and service must be simple
and direct
4. Any improvement must be made in accordance with the
scientific method, under the guidance of a teacher, at the
lowest possible level in the organization
TPS – 4 Rules
25. Lean Implementation
Empowered Workforce
Problem Solving
Performance Measurement
Total Quality
Management
Flow
Process
Stable
Schedule
Kanban
Pull
Involved
Suppliers
Continual Inventory
Reduction
Product
Design
26. Summary and Conclusions…
Lean Production is the set of activities that achieves
quality production at minimum cost and inventory
The flow of material is pulled through the process by
downstream operations
Lean originated with the Toyota Production System
and its two philosophies – elimination of waste, and
respect for people
CLOSED MITT forms of waste
