1 Toyota Production System and Lean Manufacturing D. Jorge Leon Texas A&M University 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.
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Toyota Production System and Lean Manufacturing
D. Jorge LeonTexas A&M University
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.
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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 workforceexcessive facilities
excessive inventoriesunnecessary 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
• 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
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
Characteristics:• Man Waiting for Machine• Machine/Materials Waiting for Man• Unbalanced Operations (Work)• Lack of Operator Concern for Equipment Breakdowns• Unplanned Equipment Downtime
• Extra carts, fork lifts, dollies• Multiple Storage Locations• Extra Material Racks• Complex Inventory Management• Extra Facility Space• Incorrect Inventory Counts• Damaged Material
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.
Characteristics:• Process Bottlenecks• Lack of Clear Customer Specifications• Endless Refinement• Redundant Approvals• Extra Copies/Excessive Information
Causes:• Engineering Changes Without Processing Changes• Decision Making at Inappropriate Levels• Inefficient Policies and Procedures• Lack of Customer Input Concerning Requirements
• 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,
• Incapable Processes• Uncontrolled Bottleneck Processes• Incapable Suppliers• Long Change Over Times• Management Decisions• Local Optimization• Inaccurate Forcasting Systems
• Looking for Tools• Excessive Reaching or Bending• Material Too Far Apart (Walk Time)• Equipment for Moving Parts• Extra “Busy” Movements While Waiting
• 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