1 introduction to operations management just-in-time systems chapte r 14
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1
Introduction to Operations management
Just-In-Time Systems
CHAPTER
14
2
Introduction to Operations management
Toyota Production System
The objective– Continuous improvement of the production
system (Kaizen)
3
Introduction to Operations management
Toyota Production System
Elements of the Toyota System– Just-in-time
» needed units arrived at the right time in the right amount
– Kanban system» a pull system with tight limit on work-in-process
inventory
4
Introduction to Operations management
JIT/Lean Production
Just-in-time: Repetitive production system in which processing and movement of materials and goods occur just as they are needed, usually in small batches
JIT is characteristic of lean production systems
JIT operates with very little “fat”
5
Introduction to Operations management
JIT Goals
Eliminate disruptions Make system flexible Reduce setup and lead times Minimize inventory Eliminate waste
6
Introduction to Operations management
Sources of Waste
Waste form overproduction Waste of waiting time Transportation waste Inventory waste Processing waste Waste of motion Waste from product defects
7
Introduction to Operations management
JIT Building Blocks
Product design Process design Personnel/organizational
elements Manufacturing
planning and control
8
Introduction to Operations management
Building block - Product Design
Standard parts Modular design Quality
9
Introduction to Operations management
Building block - Process Design
Small lot sizes Setup time reduction Manufacturing cells Limited work in process Quality improvement Production flexibility Little inventory storage
10
Introduction to Operations management
Benefits of Small Lot Sizes
Reduces inventory
Less storage space
Less rework
Problems are more apparent
Increases product flexibility
Easier to balance operations
11
Introduction to Operations management
JIT - variability reduction
H
2DS EOQ
Reduction in S (setup cost)
Q
12
Introduction to Operations management
JIT - Variability reduction
Reduction in safety stock
Safety Stock = ROP - = z
13
Introduction to Operations management
Building block - Production Flexibility
Reduce downtime by reducing changeover time
Use preventive maintenance to reduce breakdowns
Cross-train workers to help clear bottlenecks
Reserve capacity for important customers
14
Introduction to Operations management
JIT - flexibility
CCBBBA ABBACCC
Flow direction
Low setup cost
15
Introduction to Operations management
Building block - Personnel/Organizational Elements
Workers as assets Cross-trained workers Continuous improvement Cost accounting Leadership/project management
16
Introduction to Operations management
Building Block - Manufacturing Planning and Control
Level loading Pull systems Visual systems Close vendor relationships Reduced transaction processing
17
Introduction to Operations management
Pull/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
18
Introduction to Operations management
Kanban Production Control System
Kanban is the Japanese word for card. Paperless production control system Authority to pull, or produce comes
from a downstream process.
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Introduction to Operations management
Summary JIT Goals and Building Blocks
Product Design
ProcessDesign
PersonnelElements
Manufactur-ing Planning
Eliminate disruptionsMake the system flexible
Reduce setupand lead times
Eliminate wasteMinimize inventories
Abalancedrapid flow
UltimateGoal
SupportingGoals
BuildingBlocks
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Introduction to Operations management
Benefits of JIT Systems
Reduced levels of inventories Reduced space requirements Increased product quality Reduced lead times Greater flexibility in product mix
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Introduction to Operations management
Benefits of JIT Systems (cont’d)
Smoother production flow Increased productivity levels Worker participation in problem solving Pressure for good vendor relationships Reduced need for indirect labor
22
Introduction to Operations management
Converting 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
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Introduction to Operations management
Obstacles to Conversion
Management may not be committed Workers/management may not be
cooperative Suppliers may
resist
24
Introduction to Operations management
JIT in Service
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.