JustInTime Systems

1
Just-In-Time Systems

• Chapter 9

2
Outline

• Philosophy of JIT
• Elements of a JIT system
• Stabilizing the Master Schedule
• The Kanban System
• Reducing Setup Time and Lot Sizes

• Layout and Equipment
• Effect on Workers
• Suppliers
• Implementation of JIT
• Comparison of JIT and MRP
• Beyond JIT to Time-Based Competition

3
Philosophy of JIT

• Roots of JIT (Toyota Production System)
• Philosophical tenets of JIT
• Root of JIT in repetitive manufacturing

4
Elements of JIT

• Small lot sizes
• Use of Kanban system
• Quick changeover
• Multifunction workers
• Efficient layout
• Close relationship with supplier
• Frequent delivery of supplies

5
Elements of JIT
6
Kanban System

• A pull production system
• A physical control system
• Composed of cards and containers (production card
  and withdrawal card)
• Number of containers

7
Kanban System
8
Kanban Cards
9
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

10
JIT Layout
Final Assembly
Work Centers
Stockrooms
Supplier A
Supplier B
Initial Layout
11
JIT Layout
Final Assembly
Supplier A
Supplier B
JIT Layout
12
JIT Layout
Final Assembly
Line 1
Line 2
Supplier A
Supplier B
JIT Layout with GT
13
Effect of JIT on Workers

• Multifunction workers
• Cross-training
• New pay system to reflect skills variety
• Teamwork
• Suggestion system

14
Suppliers

• Very close relationship with suppliers
• Frequent deliveries demanded from suppliers
• Sole-sourcing
• Integrated supplier program

15
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

16
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

17
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

18
Uses of MRP and JIT
19
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