Just-In-Time Systems

1. CHAPTER 14 Just-In-Time Systems

2. Toyota Production System • The objective • Continuous improvement of the production system (Kaizen)

3. 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. 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. JIT Goals • Eliminate disruptions • Make system flexible • Reduce setup and lead times • Minimize inventory • Eliminate waste

6. Sources of Waste • Waste form overproduction • Waste of waiting time • Transportation waste • Inventory waste • Processing waste • Waste of motion • Waste from product defects

7. JIT Building Blocks • Product design • Process design • Personnel/organizationalelements • Manufacturing planning and control

8. Building block - Product Design • Standard parts • Modular design • Quality

9. Building block - Process Design • Small lot sizes • Setup time reduction • Manufacturing cells • Limited work in process • Quality improvement • Production flexibility • Little inventory storage

10. Benefits of Small Lot Sizes Reduces inventory Less rework Less storage space Problems are more apparent Increases product flexibility Easier to balance operations

11. JIT - variability reduction Reduction in S (setup cost) Q

12. JIT - Variability reduction Reduction in safety stock Safety Stock = ROP -  = z

13. 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. JIT - flexibility Low setup cost Flow direction CCBBBA ABBACCC

15. Building block - Personnel/Organizational Elements • Workers as assets • Cross-trained workers • Continuous improvement • Cost accounting • Leadership/project management

16. Building Block - Manufacturing Planning and Control • Level loading • Pull systems • Visual systems • Close vendor relationships • Reduced transaction processing

17. 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. 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.

19. Ultimate Goal A balanced rapid flow Supporting Goals Reduce setup and lead times Eliminate waste Minimize inventories Eliminate disruptions Make the system flexible Product Design Process Design Personnel Elements Manufactur-ing Planning Summary JIT Goals and Building Blocks Building Blocks

20. Benefits of JIT Systems • Reduced levels of inventories • Reduced space requirements • Increased product quality • Reduced lead times • Greater flexibility in product mix

21. 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. 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

23. Obstacles to Conversion • Management may not be committed • Workers/management may not be cooperative • Suppliers may resist

24. 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.