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© 2000 by Prentice-Hall IncRussell/Taylor Oper Mgt 3/e
Chapter 15
Just-In-Time Systems
2000 by Prentice-Hall, Inc 2Ch 15 - 2© 2000 by Prentice-Hall IncRussell/Taylor Oper Mgt 3/e
What is JIT ?
Producing only what is needed, when it is needed
A philosophy An integrated management
system. JIT’s mandate: Eliminate all waste.
2000 by Prentice-Hall, Inc 3Ch 15 - 22© 2000 by Prentice-Hall IncRussell/Taylor Oper Mgt 3/e
Inventory Hides Problems
Poor Quality
UnreliableSupplier
MachineBreakdownInefficient
Layout
BadDesign
LengthySetups
2000 by Prentice-Hall, Inc 4Ch 15 - 4© 2000 by Prentice-Hall IncRussell/Taylor Oper Mgt 3/e
Examples of Waste Watching a machine run Waiting for parts Counting parts Overproduction Moving parts over long distances Storing inventory Looking for tools Machine breakdown Rework
2000 by Prentice-Hall, Inc 5Ch 15 - 3© 2000 by Prentice-Hall IncRussell/Taylor Oper Mgt 3/e
Basic Elements of JIT1. Flexible resources2. Cellular layouts3. Pull production system4. Kanban production control5. Small-lot production6. Quick setups7. Uniform production8. Quality at the source9. Total productive maintenance
10. Supplier networks
2000 by Prentice-Hall, Inc 6Ch 15 - 5© 2000 by Prentice-Hall IncRussell/Taylor Oper Mgt 3/e
Flexible Resources
Multifunctional workers
General purpose machines
Study operators & improve operations
2000 by Prentice-Hall, Inc 7Ch 15 - 8© 2000 by Prentice-Hall IncRussell/Taylor Oper Mgt 3/e
Manufacturing Cell With Worker Routes
Enter
Worker 1
Worker 2Worker
3
Exit
Key: Product routeWorker route
Machines
2000 by Prentice-Hall, Inc 8Ch 15 - 7© 2000 by Prentice-Hall IncRussell/Taylor Oper Mgt 3/e
Cellular Layouts
Group dissimilar machines in manufacturing cell to produce family of parts
Work flows in one direction through cell
Cycle time adjusted by changing worker paths
2000 by Prentice-Hall, Inc 9Ch 15 - 10© 2000 by Prentice-Hall IncRussell/Taylor Oper Mgt 3/e
Kanban Production Control System Kanban card indicates standard
quantity of production Derived from two-bin inventory system Kanban maintains discipline of pull
production Production kanban authorizes
production Withdrawal kanban authorizes
movement of goods
2000 by Prentice-Hall, Inc 10Ch 15 - 11© 2000 by Prentice-Hall IncRussell/Taylor Oper Mgt 3/e
A Sample Kanban
MachiningM-2
AssemblyA-4
Part no.: 7412Description: Slip rings
From : To:
Box capacity 25
Box Type A
Issue No. 3/5
2000 by Prentice-Hall, Inc 11Ch 15 - 21© 2000 by Prentice-Hall IncRussell/Taylor Oper Mgt 3/e
Small-Lot Production
Requires less space & capital investment
Moves processes closer together Makes quality problems easier to
detect Makes processes more dependent
on each other
2000 by Prentice-Hall, Inc 12Ch 15 - 25© 2000 by Prentice-Hall IncRussell/Taylor Oper Mgt 3/e
Reducing Setup Time
Preset desired settings Use quick fasteners Use locator pins Prevent misalignments Eliminate tools Make movements easier
2000 by Prentice-Hall, Inc 13Ch 15 - 26© 2000 by Prentice-Hall IncRussell/Taylor Oper Mgt 3/e
Uniform Production
Results from smoothing production requirements
Kanban systems can handle +/- 10% demand changes
Smooths demand across planning horizon
Mixed-model assembly steadies component production
2000 by Prentice-Hall, Inc 14Ch 15 - 28© 2000 by Prentice-Hall IncRussell/Taylor Oper Mgt 3/e
Quality At The Source
Jidoka is authority to stop production line
Andon lights signal quality problems Undercapacity scheduling allows for
planning, problem solving & maintenance
Visual control makes problems visible Poka-yoke prevents defects
2000 by Prentice-Hall, Inc 15Ch 15 - 29© 2000 by Prentice-Hall IncRussell/Taylor Oper Mgt 3/e
Kaizen
Continuous improvement Requires total employment involvement Essence of JIT is willingness of workers to
spot quality problems halt production when necessary generate ideas for improvement analyze problems perform different functions
2000 by Prentice-Hall, Inc 16Ch 15 - 30© 2000 by Prentice-Hall IncRussell/Taylor Oper Mgt 3/e
Total Productive Maintenance (TPM) Breakdown maintenance
repairs to make failed machine operational
Preventive maintenance system of periodic inspection &
maintenance to keep machines operating
TPM combines preventive maintenance & total quality concepts
2000 by Prentice-Hall, Inc 17Ch 15 - 31© 2000 by Prentice-Hall IncRussell/Taylor Oper Mgt 3/e
TPM Requires Management To
Design products that can be easily produced on existing machines
Design machines for easier operations, changeover, maintenance
Train & retrain workers to operate machines Purchase machines that maximize
productive potential Design preventive maintenance plan
spanning life of machine
2000 by Prentice-Hall, Inc 18Ch 15 - 33© 2000 by Prentice-Hall IncRussell/Taylor Oper Mgt 3/e
Trends In Supplier Policies1. Locate near to customer2. Use small, side loaded trucks and ship mixed
loads3. Consider establishing small warehouses
near to the customer or consolidating warehouses with other suppliers
4. Use standardized containers and make deliveries according to a precise delivery schedule
5. Become a certified supplier and accept payment at regular intervals rather than upon delivery
2000 by Prentice-Hall, Inc 19Ch 15 - 34© 2000 by Prentice-Hall IncRussell/Taylor Oper Mgt 3/e
Benefits Of JIT
1. Reduced inventory
2. Improved quality
3. Lower costs
4. Reduced space requirements
5. Shorter lead time
6. Increased productivity
7. Greater flexibility8. Better relations with
suppliers9. Simplified
scheduling and control activities
10. Increased capacity11. Better use of
human resources12. More product
variety
2000 by Prentice-Hall, Inc 20Ch 15 - 35© 2000 by Prentice-Hall IncRussell/Taylor Oper Mgt 3/e
JIT Implementation
Use JIT to finely tune an operating system
Somewhat different in USA than Japan – why?
JIT is still evolving JIT isn’t for everyone
2000 by Prentice-Hall, Inc 21Ch 15 - 36© 2000 by Prentice-Hall IncRussell/Taylor Oper Mgt 3/e
JIT In Services
Competition on speed & quality Multifunctional department store
workers Work cells at fast-food restaurants Just-in-time publishing for
textbooks Construction firms receiving
material just as needed
