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Chapter 15. Just-In-Time Systems. JIT/Lean Production. 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”. JIT Goals.
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Chapter 15 Just-In-Time Systems
JIT/Lean Production • 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” MTSU Management 362
JIT Goals • Eliminate disruptions • Make system flexible • Reduce setup and lead times • Minimize inventory • Eliminate waste MTSU Management 362
Sources of Waste • Waste from overproduction • Waste of waiting time • Transportation waste • Inventory waste • Processingwaste • Waste ofmotion • Waste from product defects MTSU Management 362
JIT Building Blocks • Product design • Process design • Personnel/organizationalelements • Manufacturing planning and control MTSU Management 362
Product Design • Standard parts • Modular design • Quality MTSU Management 362
Process Design • Small lot sizes • Setup time reduction • Manufacturing cells • Limited work in process • Quality improvement • Production flexibility • Little inventory storage MTSU Management 362
Reduces inventory Less rework Less storage space Problems are more apparent Increases product flexibility Easier to balance operations Benefits of Small Lot Sizes MTSU Management 362
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 MTSU Management 362
Personnel/Organizational Elements • Workers as assets • Cross-trained workers • Continuous improvement • Cost accounting • Leadership/project management MTSU Management 362
Manufacturing Planning and Control • Level loading • Pull systems • Visual systems • Close vendor relationships • Reduced transaction processing MTSU Management 362
Pull/Push Systems • Pull system: System for moving work (material) where a workstation pulls output from the preceding station only as it is needed (e.g. Kanban) • Push system: System for moving work where output is pushed to the next station as it is completed (e.g. MRP) MTSU Management 362
Kanban Production Control System • A visible signal is used to notify the supplier (or supplying department) of the need for more material • This results in a “pull” system • Supply batches are usually very small • requires tight schedules and frequent setups • Any inventory shortage, quality problem or process failure has immediate impact MTSU Management 362
Ideal Number of Kanban Cards MTSU Management 362
Buyer Suppler Suppler Suppler Suppler Suppler Suppler Suppler Figure 15-4a Traditional Supplier Network MTSU Management 362
Buyer Suppler Figure 15-4b Tiered Supplier Network First Tier Supplier Suppler Suppler Second Tier Supplier Suppler Suppler Suppler Suppler Third Tier Supplier MTSU Management 362
Ultimate Goal A balanced rapid flow Supporting Goals Reduce setup and lead times Eliminate waste Minimize inventories Eliminate disruptions Make the system flexible Building Blocks Product Design Process Design Personnel Elements Manufacturing Planning Figure 15-3 Summary JIT Goals and Building Blocks MTSU Management 362
Benefits of JIT Systems (1 of 2) • Reduced levels of inventories • Reduced space requirements • Increased product quality • Reduced lead times • Greater flexibility in product mix MTSU Management 362
Benefits of JIT Systems (2 of 2) • Smoother production flow • Increased productivity levels • Worker participation in problem solving • Pressure for good vendor relationships • Reduced need for indirect labor MTSU Management 362
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 MTSU Management 362
Obstacles to Conversion • Management may not be committed • Workers/management may not be cooperative • Suppliers may resist MTSU Management 362
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 • Eliminate disruptions • Make system flexible • Reduce setup and lead times • Eliminate waste • Minimize WIP • Simplify the process MTSU Management 362