chapter15 just in time technique new.ppt

presentation

1. McGraw-Hill/Irwin Copyright © 2007 by The McGraw-Hill Companies, Inc. All rights reserved.
1515
JIT and
Lean Operations

2. 15-2
Learning ObjectivesLearning Objectives
Explain what is meant by the term lean operations
system.
List each of the goals of JIT and explain its
importance.
List and briefly describe the building blocks of JIT.
List the benefits of the JIT system.
Outline the considerations important in converting
a traditional mode of operations to a JIT system.
List some of the obstacles that might be
encountered when converting to a JIT system.

3. 15-3
JIT/Lean ProductionJIT/Lean Production
Just-in-time (JIT): A highly
coordinated processing system in which
goods move through the system, and
services are performed, just as they are
needed,
JIT   lean production
JIT  pull (demand) system
JIT operates with very little “fat”

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Goal of JITGoal of JIT
The ultimate goal of JIT is a balanced
system.
Achieves a smooth, rapid flow of
materials through the system

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Summary JIT Goals and Building Summary JIT Goals and Building
BlocksBlocksFigure 15.1
Product
Design
Process
Design
Personnel
Elements
Manufactur-
ing Planning
Eliminate disruptions
Make the system flexible
Eliminate waste
A
balanced
rapid flow
Ultimate
Goal
Supporting
Goals
Building
Blocks

6. 15-6
Supporting GoalsSupporting Goals
Eliminate disruptions
Make system flexible
Eliminate waste, especially excess
inventory

7. 15-7
Sources of WasteSources of Waste
Overproduction
Waiting time
Unnecessary transportation
Processing waste
Inefficient work methods
Product defects

8. 15-8
Kaizen PhilosophyKaizen Philosophy
Waste is the enemy
Improvement should be done gradually and
continuously
Everyone should be involved
Built on a cheap strategy
Can be applied anywhere

9. 15-9
Kaizen Philosophy (cont’d)Kaizen Philosophy (cont’d)
Supported by a visual system
Focuses attention where value is created
Process oriented
Stresses main effort of improvement should
come from new thinking and work style
The essence of organizational learning is to
learn while doing

10. 15-10
Big JIT – broad focus
Vendor relations
Human relations
Technology management
Materials and inventory management
Little JIT – narrow focus
Scheduling materials
Scheduling services of production
Big vs. Little JITBig vs. Little JIT

11. 15-11
JIT Building BlocksJIT Building Blocks
Product design
Process design
Personnel/organizational
elements
Manufacturing
planning and control

12. 15-12
Product DesignProduct Design
Standard parts
Modular design
Highly capable production systems
Concurrent
engineering

13. 15-13
Process DesignProcess Design
Small lot sizes
Setup time reduction
Manufacturing cells
Limited work in process
Quality improvement
Production flexibility
Balanced system
Little inventory storage

14. 15-14
Benefits of Small Lot SizesBenefits of Small Lot Sizes
Reduces inventory
Less storage space
Less rework
Problems are more apparent
Increases product flexibility
Easier to balance operations

15. 15-15
Single-Minute ExchangeSingle-Minute Exchange
Single-minute exchange of die (SMED): A
system for reducing changeover time
Categorize changeover activities
Internal – activities that can only be done while
machine is stopped
External – activities that do not require stopping
the machine

16. 15-16
Production FlexibilityProduction Flexibility
Reduce downtime by reducing
changeover time
Use preventive maintenance to
reduce breakdowns
Cross-train workers to help clear
bottlenecks

17. 15-17
Production Flexibility (cont’d)Production Flexibility (cont’d)
Use many small units of capacity
Use off-line buffers
Reserve capacity for important customers

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Quality ImprovementQuality Improvement
Autonomation
Automatic detection of defects during
production
Jidoka
Japanese term for autonomation

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Production FlexibilityProduction Flexibility
Balance system: Distributing the workload
evenly among work stations
Work assigned to each work station must be
less than or equal to the cycle time
Cycle time is set equal to the takt time
Takt time is the cycle time needed to match
customer demand for final product

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Personnel/Organizational Personnel/Organizational
ElementsElements
Workers as assets
Cross-trained
workers
Continuous
improvement
Cost accounting
Leadership/project
management

21. 15-21
Manufacturing Planning and Manufacturing Planning and
ControlControl
Level loading
Pull systems
Visual systems
Close vendor relationships
Reduced transaction
processing
Preventive maintenance

22. 15-22
Pull/Push SystemsPull/Push Systems
Pull system: System for moving work
where a workstation pulls output from
the preceding station as needed. (e.g.
Kanban)
Push system: System for moving work
where output is pushed to the next
station as it is completed

23. 15-23
Kanban Production Control Kanban Production Control
SystemSystem
Kanban: Card or other device that
communicates demand for work or
materials from the preceding station
Kanban is the Japanese word meaning
“signal” or “visible record”
Paperless production control system
Authority to pull, or produce comes
from a downstream process.

24. 15-24
Kanban FormulaKanban Formula
N =
DT(1+X)
C
N = Total number of containers
D = Planned usage rate of using work center
T = Average waiting time for replenishment of parts
plus average production time for a
container of parts
X = Policy variable set by management
- possible inefficiency in the system
C = Capacity of a standard container

25. 15-25
Limited Work in ProcessLimited Work in Process
Benefits
Lower carrying costs
Increased flexibility
Aids scheduling
Saves cost of rework and scrap
Two general approaches
Kanban – focuses on individual work stations
Constant work in process (CONWIP) – focuses
on the system as a whole

26. 15-26
Traditional Supplier NetworkTraditional Supplier Network
Buyer
SupplierSupplier
SupplierSupplier
Supplier
Supplier
Supplier
Figure 15.4a

27. 15-27
Tiered Supplier NetworkTiered Supplier Network
Figure 15.4b
Supplier
Supplier
Supplier
SupplierSupplierSupplier
Buyer
SupplierFirst Tier SupplierFirst Tier Supplier
Second Tier SupplierSecond Tier Supplier
Third Tier SupplierThird Tier Supplier

28. 15-28
Preventive Maintenance andPreventive Maintenance and
HousekeepingHousekeeping
Preventative maintenance: Maintaining
equipment in good condition and replacing
parts that have a tendency to fail before they
actually fail.
Housekeeping: Maintaining a workplace that
is clean and free of unnecessary materials.

29. 15-29
Housekeeping Five S’sHousekeeping Five S’s
1.Sort
2.Straighten
3.Sweep
4.Standardize
5.Self-discipline

30. 15-30
Comparison of JIT and Comparison of JIT and
TraditionalTraditional
Factor Traditional JIT
Inventory
Much to offset forecast
errors, late deliveries
Minimal necessary to operate
Deliveries
Few, large Many, small
Lot sizes
Large Small
Setup; runs
Few, long runs Many, short runs
Vendors
Long-term relationships
are unusual
Partners
Workers
Necessary to do the workAssets
Table 15.3

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Transitioning to a JIT SystemTransitioning to a JIT System
Get top management commitment
Decide which parts need most effort
Obtain support of workers
Start by trying to reduce setup times
Gradually convert operations
Convert suppliers to JIT
Prepare for obstacles

32. 15-32
Obstacles to ConversionObstacles to Conversion
Management may not be committed
Workers/management may not be
cooperative
Difficult to change company culture
Suppliers may
resist
 Why?

33. 15-33
Suppliers May Resist JITSuppliers May Resist JIT
Unwilling to commit resources
Uneasy about long-term commitments
Frequent, small deliveries may be difficult
Burden of quality control shifts to supplier
Frequent engineering changes may cause
JIT changes

34. 15-34
JIT in ServicesJIT in Services
The basic goal of the demand flow technology in
the service organization is to provide optimum
response to the customer with the highest
quality service and lowest possible cost.
Eliminate disruptions
Make system flexible
Reduce setup and lead times
Eliminate waste
Minimize WIP
Simplify the process

35. 15-35
JIT II: a supplier representative works
right in the company’s plant, making
sure there is an appropriate supply on
hand.
JIT IIJIT II

36. 15-36
Benefits of JIT SystemsBenefits of JIT Systems
Reduced inventory levels
High quality
Flexibility
Reduced lead times
Increased productivity

37. 15-37
Benefits of JIT Systems (cont’d)Benefits of JIT Systems (cont’d)
Increased equipment utilization
Reduced scrap and rework
Reduced space requirements
Pressure for good vendor relationships
Reduced need for indirect labor

38. 15-38
Smooth flow of work (the ultimate goal)
Elimination of waste
Continuous improvement
Eliminating anything that does not add
value
Simple systems that are easy to manage
Use of product layouts to minimize
moving materials and parts
Quality at the source
Elements of JITElements of JIT
Table 15.4

39. 15-39
Poka-yoke – fail safe tools and methods
Preventative maintenance
Good housekeeping
Set-up time reduction
Cross-trained employees
A pull system
Elements of JIT (cont’d)Elements of JIT (cont’d)
Table 15.4

40. 15-40
Video: Made for youVideo: Made for you

41. 15-41
Video: New systemVideo: New system

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Video: McDonald’s ProcessVideo: McDonald’s Process

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Video: Layout GortracVideo: Layout Gortrac