Chap 16 Just-In-time Systems
27
16-1 McGraw-Hill/Irwin Operations Management, Seventh Edition, by William J. Stevenson Copyright © 2002 by The McGraw-Hill Companies, Inc. All rights reserved. Just-in-Time Systems Chapter 16 Just-In-Time Systems
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Transcript of Chap 16 Just-In-time Systems
16-1
McGraw-Hill/IrwinOperations Management, Seventh Edition, by William J. StevensonCopyright © 2002 by The McGraw-Hill Companies, Inc. All rights reserved.
Just-in-Time Systems
Chapter 16
Just-In-Time Systems
16-2
McGraw-Hill/IrwinOperations Management, Seventh Edition, by William J. StevensonCopyright © 2002 by The McGraw-Hill Companies, Inc. All rights reserved.
Just-in-Time Systems
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”
16-3
McGraw-Hill/IrwinOperations Management, Seventh Edition, by William J. StevensonCopyright © 2002 by The McGraw-Hill Companies, Inc. All rights reserved.
Just-in-Time Systems
JIT Goals
• Eliminate disruptions
• Make system flexible by reduce setup and lead times
• Eliminate waste, especially excess inventory
16-4
McGraw-Hill/IrwinOperations Management, Seventh Edition, by William J. StevensonCopyright © 2002 by The McGraw-Hill Companies, Inc. All rights reserved.
Just-in-Time Systems
Sources of Waste
• Overproduction• Waiting time• Unnecessary transportation• Processing waste• Inefficient work methods• Product defects
16-5
McGraw-Hill/IrwinOperations Management, Seventh Edition, by William J. StevensonCopyright © 2002 by The McGraw-Hill Companies, Inc. All rights reserved.
Just-in-Time Systems
• 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 JIT
16-6
McGraw-Hill/IrwinOperations Management, Seventh Edition, by William J. StevensonCopyright © 2002 by The McGraw-Hill Companies, Inc. All rights reserved.
Just-in-Time Systems
JIT Building Blocks
• Product design• Process design• Personnel/organizational
elements• Manufacturing
planning and control
16-7
McGraw-Hill/IrwinOperations Management, Seventh Edition, by William J. StevensonCopyright © 2002 by The McGraw-Hill Companies, Inc. All rights reserved.
Just-in-Time Systems
Product Design
• Standard parts
• Modular design
• Highly capable production systems
16-8
McGraw-Hill/IrwinOperations Management, Seventh Edition, by William J. StevensonCopyright © 2002 by The McGraw-Hill Companies, Inc. All rights reserved.
Just-in-Time Systems
Process Design• Small lot sizes• Setup time reduction• Manufacturing cells• Limited work in process• Quality improvement• Production flexibility• Little inventory storage
16-9
McGraw-Hill/IrwinOperations Management, Seventh Edition, by William J. StevensonCopyright © 2002 by The McGraw-Hill Companies, Inc. All rights reserved.
Just-in-Time Systems
Benefits of Small Lot Sizes
Reduces inventory
Less storage spaceLess rework
Problems are more apparent
Increases product flexibilityEasier to balance operations
16-10
McGraw-Hill/IrwinOperations Management, Seventh Edition, by William J. StevensonCopyright © 2002 by The McGraw-Hill Companies, Inc. All rights reserved.
Just-in-Time Systems
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
16-11
McGraw-Hill/IrwinOperations Management, Seventh Edition, by William J. StevensonCopyright © 2002 by The McGraw-Hill Companies, Inc. All rights reserved.
Just-in-Time Systems
Personnel/Organizational Elements
• Workers as assets
• Cross-trained workers
• Continuous improvement
• Cost accounting
• Leadership/project management
16-12
McGraw-Hill/IrwinOperations Management, Seventh Edition, by William J. StevensonCopyright © 2002 by The McGraw-Hill Companies, Inc. All rights reserved.
Just-in-Time Systems
Manufacturing Planning and Control
• Level loading• Pull systems• Visual systems• Close vendor relationships• Reduced transaction
processing• Preventive maintenance
16-13
McGraw-Hill/IrwinOperations Management, Seventh Edition, by William J. StevensonCopyright © 2002 by The McGraw-Hill Companies, Inc. All rights reserved.
Just-in-Time Systems
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
16-14
McGraw-Hill/IrwinOperations Management, Seventh Edition, by William J. StevensonCopyright © 2002 by The McGraw-Hill Companies, Inc. All rights reserved.
Just-in-Time Systems
Kanban Production Control System
• 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.
16-15
McGraw-Hill/IrwinOperations Management, Seventh Edition, by William J. StevensonCopyright © 2002 by The McGraw-Hill Companies, Inc. All rights reserved.
Just-in-Time Systems
Traditional Supplier Network
Buyer
SupplierSupplier Supplier Suppiler
Supplier
Supplier
Supplier
Figure 16-3a
16-16
McGraw-Hill/IrwinOperations Management, Seventh Edition, by William J. StevensonCopyright © 2002 by The McGraw-Hill Companies, Inc. All rights reserved.
Just-in-Time Systems
Tiered Supplier Network
Figure 16-3b
Supplier
Supplier
Supplier
SupplierSupplier Supplier
Buyer
SupplierFirst Tier Supplier
Second Tier Supplier
Third Tier Supplier
16-17
McGraw-Hill/IrwinOperations Management, Seventh Edition, by William J. StevensonCopyright © 2002 by The McGraw-Hill Companies, Inc. All rights reserved.
Just-in-Time Systems
Summary JIT Goals and Building Blocks
Figure 16-4
Product Design
ProcessDesign
PersonnelElements
Manufactur-ing Planning
Eliminate disruptionsMake the system flexible
Reduce setupand lead times
Eliminate wasteMinimize inventories
Abalancedrapid flow
UltimateGoal
SupportingGoals
BuildingBlocks
16-18
McGraw-Hill/IrwinOperations Management, Seventh Edition, by William J. StevensonCopyright © 2002 by The McGraw-Hill Companies, Inc. All rights reserved.
Just-in-Time Systems
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
16-19
McGraw-Hill/IrwinOperations Management, Seventh Edition, by William J. StevensonCopyright © 2002 by The McGraw-Hill Companies, Inc. All rights reserved.
Just-in-Time Systems
Obstacles to Conversion
• Management may not be committed
• Workers/management may not be cooperative
• Suppliers may resist
16-20
McGraw-Hill/IrwinOperations Management, Seventh Edition, by William J. StevensonCopyright © 2002 by The McGraw-Hill Companies, Inc. All rights reserved.
Just-in-Time Systems
JIT in ServiceThe 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
16-21
McGraw-Hill/IrwinOperations Management, Seventh Edition, by William J. StevensonCopyright © 2002 by The McGraw-Hill Companies, Inc. All rights reserved.
Just-in-Time Systems
• New challenges– Meeting manufacturing requirements– Changing from traditional thinking and
practices – frequent on-time delivery of small quantities
– Long term relationships with suppliers as partners
JIT Purchasing
16-22
McGraw-Hill/IrwinOperations Management, Seventh Edition, by William J. StevensonCopyright © 2002 by The McGraw-Hill Companies, Inc. All rights reserved.
Just-in-Time Systems
• JIT II: the practice of allowing vendors to manage some aspects of buying their products or services for the buyer
JIT II
16-23
McGraw-Hill/IrwinOperations Management, Seventh Edition, by William J. StevensonCopyright © 2002 by The McGraw-Hill Companies, Inc. All rights reserved.
Just-in-Time Systems
Benefits of JIT Systems
• Reduced inventory levels
• High quality
• Flexibility
• Reduced lead times
• Increased productivity
16-24
McGraw-Hill/IrwinOperations Management, Seventh Edition, by William J. StevensonCopyright © 2002 by The McGraw-Hill Companies, Inc. All rights reserved.
Just-in-Time Systems
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
16-25
McGraw-Hill/IrwinOperations Management, Seventh Edition, by William J. StevensonCopyright © 2002 by The McGraw-Hill Companies, Inc. All rights reserved.
Just-in-Time Systems
• Waste from overproduction• Waste of waiting time• Transportation waste• Inventory waste• Processing waste• Waste of motion• Waste from product defects
Sources of WasteTable 16-5
16-26
McGraw-Hill/IrwinOperations Management, Seventh Edition, by William J. StevensonCopyright © 2002 by The McGraw-Hill Companies, Inc. All rights reserved.
Just-in-Time Systems
• 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
Table 16-5Elements of JIT
16-27
McGraw-Hill/IrwinOperations Management, Seventh Edition, by William J. StevensonCopyright © 2002 by The McGraw-Hill Companies, Inc. All rights reserved.
Just-in-Time Systems
• Poka-yoke – fail safe tools and methods• Preventative maintenance• Good houskeeping• Set-up time reduction
• Cross-trained employees
• A pull system
Elements of JIT (cont’d)Table 16-5
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