Seven wastes


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Seven wastes

  1. 1. Toyota Production System and Lean Manufacturing TOYOTA PRODUCTION SYSTEM The Toyota Production System was adopted by many Japanese companies in the aftermath of the 1973 oil shock “Waste” Elimination Philosophy: “.. Above all, one of our most important purposes was increased productivity and reduced cost. To achieve this purpose, we put our emphasis on the notion of eliminating all kinds of unnecessary functions in the factories. Our approach has been to investigate one by one the causes of various "unnecessaries" in manufacturing operations and to devise methods for their solution, often by trial and error ...” Taiicho Ohno, Former Vice President, Toyota Motor Corp., Former President, Japan Industrial Management Association; Former Chairman, Toyoda Spinning and Weaving Co., Ltd.
  2. 2. PURPOSES OF JIT Primary Purpose: Profit through cost reduction (or improvement of Productivity) This is attained through WASTE elimination. Other important purposes: Quantity control: JIT, Kanban & Autonomation (visual control system) Quality control: Autonomation, improvement by small groups, functional management Respect for humanity: Flexible work force (adapt to demand changes), capitalize workers ideas. TYPES OF WASTE Excessive production resources (primary waste): excessive workforce excessive facilities excessive inventories unnecessary capital investment Overproduction (secondary waste - the WORST waste): leads to Excessive inventories (tertiary waste): extra jobs make overproduction invisible. adds losses in opportunity cost lead to Unnecessary capital investment (fourth waste): adds facility depreciations and overhead cost
  3. 3. TO ACHIEVE THESE PUPOSES 7 Wastes Elimination Just-In-Time (JIT) Production Kanban System Production Smoothing 5S Setup Time Reduction Machine Layout & Multi-function Worker Autonomation (Visual Management)
  4. 4. Identification and Elimination of Waste Philosophy •Identification and elimination of waste is the central theme of a lean manufacturing production system •Lean manufacturing is a dynamic and constantly improving process dependent upon understanding and involvement by all employees •Successful implementation requires that all employees must be trained to identify and eliminate waste from their work •Waste exists in all work and at all levels in the organization
  5. 5. t , Identification and Elimination of Waste Philosophy Effectiveness is the result of the integration of:- Man - Method - Material - Machine At the worksite • Waste exists in all work and at all levels in the organization Seven Types of Waste Over-production Wait time Transportation Processing Inventory Motion Defects
  6. 6. Over-production Waste Definition Producing more than needed Producing faster than needed Over-production Waste Characteristics: •Inventory Stockpiles •Extra equipment/oversized equipment •Unbalanced Material Flow •Extra Part Storage racks •Extra Manpower •Batch Processing •Complex Inventory Management •Excessive Capacity/Investment •Additional Floor Space/Outside Storage •Hidden Problems •Excessive Obsolescence •Large Lot Sizes •Building Ahead
  7. 7. Over-production Waste Causes: •Incapable Processes •Just in Case Reward System •Lack of Communication •Local Optimization •Automation in the Wrong Places •Cost Accounting Practices •Low Uptimes •Lack of Stable/Consitent Schedules Waiting Time Waste Definition Idle Time That is Produced When Two Dependant Variables are not Fully Synchronized. •Man Wait Time •Machine Wait Time
  8. 8. Waiting Time Waste Characteristics: •Man Waiting for Machine •Machine/Materials Waiting for Man •Unbalanced Operations (Work) •Lack of Operator Concern for Equipment Breakdowns •Unplanned Equipment Downtime Waiting Time Waste Causes: •Inconsistent Work Methods •Long Machine Change Over Time •Low Man/Machine Effectiveness •Lack of Proper Equipment/Materials
  9. 9. Transportation Waste Definition Any Material Movement That Does Not Directly Support a Lean Manufacturing System Transportation Waste Characteristics: •Extra carts, fork lifts, dollies •Multiple Storage Locations •Extra Material Racks •Complex Inventory Management •Extra Facility Space •Incorrect Inventory Counts •Damaged Material
  10. 10. Transportation Waste Causes: •Large Lot Processing •Unleveled Schedules •Lack of 5 S’s •Lack of Visual Controls •Improper Facility Layout •Large Buffers and In Process Kanbans Processing Waste Definitio n Effort Which Adds No Value To a Product or Service. Enhancements which are Transparent to The Customers or Work Which Could Be Combined with Another Process.
  11. 11. Processing Waste Characteristics: •Process Bottlenecks •Lack of Clear Customer Specifications •Endless Refinement •Redundant Approvals •Extra Copies/Excessive Information Processing Waste Causes: •Engineering Changes Without Processing Changes •Decision Making at Inappropriate Levels •Inefficient Policies and Procedures •Lack of Customer Input Concerning Requirements
  12. 12. Inventory Waste Definition Any Supply in Excess of Process Requirements Necessary to Produce Goods or Services Just in Time. Inventory Waste Characteristics: •Extra Space on Receiving Docks •Material Between Processes •Stagnated Material Flow •LIFO instead of FIFO •Extensive Rework When Problems Surface •Long Lead Time for Engineering Changes •Additional Material Handling Resources (Men, Equipment, Racks, Storage Space)
  13. 13. Inventory Level Over Production Wait Time Inventory Waste Causes: •Incapable Processes •Uncontrolled Bottleneck Processes •Incapable Suppliers •Long Change Over Times •Management Decisions •Local Optimization •In times Process Defects Motion Waste Definition Any Movement of People Which Does Not Contribute Added Value To The Product or Service
  14. 14. Motion Waste Characteristics: •Looking for Tools •Excessive Reaching or Bending •Material Too Far Apart (Walk Time) •Equipment for Moving Parts •Extra “Busy” Movements While Waiting Motion Waste Causes: •Equipment, Office & Plant Layout •Lack of 5 S’s •Lack of Visual Controls •Inconsistent Work Methods (Standardized Work) •Large Batch Sizes
  15. 15. Rework or Correction Waste Definitio n Repair of a Product or Service To Fulfill Customer requirements Rework or Correction Waste Characteristics: •Extra Floor Space/Tools/Equipment •Extra Manpower To Inspect/Rework/Repair •Stockpiling Inventory •Complex Material Flow •Questionable Quality •Missed Shipments/Deliveries •Lower Profits Due To Scrap •Reactive Organization
  16. 16. Rework or Correction Waste Causes: •Incapable Processes •Excessive Variation •Incapable Suppliers •Management Decisions •Insufficient Training •Inadequate Tools/Equipment •Poor Layouts/Unnecessary Handling •High Inventory Levels Seven Types of Waste Over-production Wait Transportation Processing Inventory Motion Defects
  17. 17. Seven Types of Waste