Just-In-Time Systems Chapter 17 Irwin/McGraw-Hill The McGraw-Hill Companies, Inc. 2004 1 Outline Philosophy of JIT Elements of a JIT system Stabilizing the Master Schedule The Kanban System Reducing Setup Time and Lot Sizes Irwin/McGraw-Hill Layout and Equipment Effect on Workers Suppliers Implementation of JIT Comparison of JIT and MRP Beyond JIT to TimeBased Competition The McGraw-Hill Companies, Inc. 2004 2 Philosophy of JIT Roots of JIT (Toyota Production System) Philosophical tenets of JIT Root of JIT in “repetitive” manufacturing Irwin/McGraw-Hill The McGraw-Hill Companies, Inc. 2004 3 The Seven Wastes (Table 17.1) Overproduction: Producing more than the demand for customers resulting in unnecessary inventory, handling, paperwork, and warehouse space. Waiting Time: Operators and machines waiting for parts or work to arrive from suppliers or other operations. Transportation: Double or triple movement of materials due to poor layouts, lack of coordination and workplace organization. Processing: Poor design or inadequate maintenance or processes requiring additional labor or machine time. Inventory: Excess inventory due to large lot sizes, obsolete items, poor forecasts or improper production planning. Motion: Wasted movements of people or extra walking to get materials. Defects: Use of materials, labor and capacity for production of defects, sorting our bad parts or warranty costs with customers. Irwin/McGraw-Hill The McGraw-Hill Companies, Inc. 2004 4 Elements of JIT (See Figure17.1) Small lot sizes Use of Kanban system Quick changeover Multifunction workers Efficient layout Close relationship with supplier Frequent delivery of supplies Irwin/McGraw-Hill The McGraw-Hill Companies, Inc. 2004 5 Elements of JIT S e t u p T i m e R e d u c t i o n S m a l l L o t S i z e s J I T D e l i v e r y f r o m S u p p l i e r s S u p p l i e r s ' Q u a l i t y L e v e l P r o d u c t D e s i g n S i m p l i c i t y M u l t i f u n c t i o n W o r k e r s E q u i p m e n t & F a c i l i t y L a y o u t S m a l l G r o u p P r o b l e m S o l v i n g J I T P r e v e n t i v e M a i n t e n a n c e K A N B A N S y s t e m Irwin/McGraw-Hill E m p l o y e e T r a i n i n g R e p e t i t i v e M P S D a i l y S c h e d u l e D i s c i p l i n e " P u l l " P r o d u c t i o n S y s t e m The McGraw-Hill Companies, Inc. 2004 6 Kanban System A “pull” production system A physical control system Composed of cards and containers (production card and withdrawal card) Number of containers n DT C Irwin/McGraw-Hill The McGraw-Hill Companies, Inc. 2004 7 Kanban System (Figure 17.3) Irwin/McGraw-Hill The McGraw-Hill Companies, Inc. 2004 8 Kanban Cards (Figure 17.4) Irwin/McGraw-Hill The McGraw-Hill Companies, Inc. 2004 9 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 (Shigeo Shingo System) Irwin/McGraw-Hill The McGraw-Hill Companies, Inc. 2004 10 JIT Layout: Figure 17.7(a) Work Centers Final Assembly Stockrooms Supplier A Supplier B Initial Layout Irwin/McGraw-Hill The McGraw-Hill Companies, Inc. 2004 11 JIT Layout: Figure 17.7(b) Final Assembly Supplier A Supplier B JIT Layout Irwin/McGraw-Hill The McGraw-Hill Companies, Inc. 2004 12 JIT Layout: Figure 17.7(c) Final Assembly Line 1 Line 2 Supplier A Supplier B JIT Layout with GT Irwin/McGraw-Hill The McGraw-Hill Companies, Inc. 2004 13 Effect of JIT on Workers Multifunction workers Cross-training New pay system to reflect skills variety Teamwork Suggestion system Irwin/McGraw-Hill The McGraw-Hill Companies, Inc. 2004 14 Suppliers Very close relationship with suppliers Frequent deliveries demanded from suppliers Sole-sourcing Integrated supplier program Irwin/McGraw-Hill The McGraw-Hill Companies, Inc. 2004 15 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 Irwin/McGraw-Hill The McGraw-Hill Companies, Inc. 2004 16 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 Irwin/McGraw-Hill The McGraw-Hill Companies, Inc. 2004 17 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 Irwin/McGraw-Hill The McGraw-Hill Companies, Inc. 2004 18 Uses of MRP and JIT (Figure 17.7) JIT Repetitive (mass) MRP SYNCRO MRP Nonrepetitive Semirepetitive (batch or job shop) JIT SYNCRO MRP MRP High Low Stability of Master Schedule Stability of Bill of Material Irwin/McGraw-Hill The McGraw-Hill Companies, Inc. 2004 19 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 Irwin/McGraw-Hill The McGraw-Hill Companies, Inc. 2004 20