210 likes | 456 Vues
Just-In-Time Systems. Chapter 9. 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
E N D
Just-In-Time Systems Chapter 9
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 Outline
Philosophy of JIT • Roots of JIT (Toyota Production System) • Philosophical tenets of JIT • Root of JIT in “repetitive” manufacturing
Elements of JIT • Small lot sizes • Use of Kanban system • Quick changeover • Multifunction workers • Efficient layout • Close relationship with supplier • Frequent delivery of supplies
Kanban System • A “pull” production system • A physical control system • Composed of cards and containers (production card and withdrawal card) • Number of containers
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
JIT Layout Final Assembly Work Centers Stockrooms Supplier A Supplier B Initial Layout
JIT Layout Final Assembly Supplier A Supplier B JIT Layout
JIT Layout Final Assembly Line 1 Line 2 Supplier A Supplier B JIT Layout with GT
Effect of JIT on Workers • Multifunction workers • Cross-training • New pay system to reflect skills variety • Teamwork • Suggestion system
Suppliers • Very close relationship with suppliers • Frequent deliveries demanded from suppliers • Sole-sourcing • Integrated supplier program
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
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
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
JIT JIT Repetitive (mass) SYNCRO MRP MRP Nonrepetitive (batch or job shop) SYNCRO MRP Semirepetitive MRP High Low Stability of Master Schedule Stability of Bill of Material Uses of MRP and JIT
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