Just-In-Time Systems
Chapter 17
Irwin/McGraw-Hill
 The McGraw-Hill Companies, Inc. 2004
1
Outline
Philosophy of JIT
Elements of a JIT system
Stabilizing the Master
Schedule
The Kanban System
Reducing Setup Time
and Lot Sizes
Irwin/McGraw-Hill
Layout and Equipment
Effect on Workers
Suppliers
Implementation of JIT
Comparison of JIT and
MRP
Beyond JIT to TimeBased Competition
 The McGraw-Hill Companies, Inc. 2004
2
Philosophy of JIT
Roots of JIT (Toyota Production System)
Philosophical tenets of JIT
Root of JIT in “repetitive” manufacturing
Irwin/McGraw-Hill
 The McGraw-Hill Companies, Inc. 2004
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The Seven Wastes (Table 17.1)
Overproduction: Producing more than the demand for customers resulting in
unnecessary inventory, handling, paperwork, and warehouse space.
Waiting Time: Operators and machines waiting for parts or work to arrive from
suppliers or other operations.
Transportation: Double or triple movement of materials due to poor layouts, lack
of coordination and workplace organization.
Processing: Poor design or inadequate maintenance or processes requiring
additional labor or machine time.
Inventory: Excess inventory due to large lot sizes, obsolete items, poor forecasts
or improper production planning.
Motion: Wasted movements of people or extra walking to get materials.
Defects: Use of materials, labor and capacity for production of defects, sorting our
bad parts or warranty costs with customers.
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 The McGraw-Hill Companies, Inc. 2004
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Elements of JIT (See Figure17.1)
Small lot sizes
Use of Kanban system
Quick changeover
Multifunction workers
Efficient layout
Close relationship with supplier
Frequent delivery of supplies
Irwin/McGraw-Hill
 The McGraw-Hill Companies, Inc. 2004
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Elements of JIT
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 The McGraw-Hill Companies, Inc. 2004
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Kanban System
A “pull” production system
A physical control system
Composed of cards and containers
(production card and withdrawal card)
Number of containers n  DT
C
Irwin/McGraw-Hill
 The McGraw-Hill Companies, Inc. 2004
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Kanban System (Figure 17.3)
Irwin/McGraw-Hill
 The McGraw-Hill Companies, Inc. 2004
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Kanban Cards (Figure 17.4)
Irwin/McGraw-Hill
 The McGraw-Hill Companies, Inc. 2004
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Reducing Setup Time and Lot Sizes
Reducing setup time:
– increases available capacity
– increases flexibility
– reduces inventory
Reducing setup times and run times
simultaneously
Single-digit Setup Times (Shigeo Shingo
System)
Irwin/McGraw-Hill
 The McGraw-Hill Companies, Inc. 2004
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JIT Layout: Figure 17.7(a)
Work Centers
Final
Assembly
Stockrooms
Supplier A
Supplier B
Initial Layout
Irwin/McGraw-Hill
 The McGraw-Hill Companies, Inc. 2004
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JIT Layout: Figure 17.7(b)
Final
Assembly
Supplier A
Supplier B
JIT Layout
Irwin/McGraw-Hill
 The McGraw-Hill Companies, Inc. 2004
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JIT Layout: Figure 17.7(c)
Final
Assembly
Line 1
Line 2
Supplier A
Supplier B
JIT Layout with GT
Irwin/McGraw-Hill
 The McGraw-Hill Companies, Inc. 2004
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Effect of JIT on Workers
Multifunction workers
Cross-training
New pay system to reflect skills variety
Teamwork
Suggestion system
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 The McGraw-Hill Companies, Inc. 2004
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Suppliers
Very close relationship with suppliers
Frequent deliveries demanded from
suppliers
Sole-sourcing
Integrated supplier program
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 The McGraw-Hill Companies, Inc. 2004
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Features of Integrated Supplier Programs
Early supplier selection
Family of part sourcing
Long-term relationship
Cost-analysis-based price negotiations
Paperwork reduction in receiving and
inspection
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 The McGraw-Hill Companies, Inc. 2004
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Implementation of JIT
Obtain commitment from top management
Gain the cooperation of workforce
Start with final assembly line
Reduce setup times and lot sizes working
backward from the final assembly line
Balance fabrication rates with final assembly
production rates
Extend JIT to the suppliers
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 The McGraw-Hill Companies, Inc. 2004
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Comparison of MRP and JIT
Pull versus Push production systems
Situations for comparing MRP and JIT:
– Pure repetitive manufacturing situation
– A batch process
– A job shop
Irwin/McGraw-Hill
 The McGraw-Hill Companies, Inc. 2004
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Uses of MRP and JIT (Figure 17.7)
JIT
Repetitive (mass)
MRP
SYNCRO MRP Nonrepetitive
Semirepetitive (batch or job
shop)
JIT
SYNCRO MRP
MRP
High
Low
Stability of Master Schedule
Stability of Bill of Material
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 The McGraw-Hill Companies, Inc. 2004
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Time-Based Competition (TBC)
Basic idea: Compete on time, as well as
quality, flexibility, and cost.
Use of technology (CAD, CAE, CAM) in
TBC
Extending JIT beyond the factory floor (to
sales, finance, accounting, etc.)
Application of TBC in the service sector
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 The McGraw-Hill Companies, Inc. 2004
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