精益生产_精益企业的基本原则

Deborah Nightingale 2002 Massachusetts Institute of Technology 1 Fundamentals of Lean Professor Deborah Nightingale September 9, 2002 Deborah Nightingale 2002 Massachusetts Institute of Technology 2 Lean is a New Approach to Managing Enterprises Origin and evolution of lean concepts Core lean principles variability reduction; quality designed- in, not based on inspection Flexibility and responsiveness: Small lot sizes and quick set-up times; ability to respond to shifts in demand Trust-based relationships: Mutual commitments and obligations, internally and externally with suppliers Continuous improvement (Kaizen): Continuous improvement through work standardization, productive maintenance, error proofing, root cause analysis, and worker training & empowerment Deborah Nightingale 2002 Massachusetts Institute of Technology 12 5 Steps to Becoming Lean Northrop Grumman ISS * 4 3 2 1 5 Deborah Nightingale 2002 Massachusetts Institute of Technology 13 1. Define Value 2. Identify the Value Stream 3. Flow the Product 4. Pull 5. Strive for Perfection Customer Follow the Product Eliminate Waste Produce Just-in-Time Continuously Improve 5 Steps to Becoming Lean Deborah Nightingale 2002 Massachusetts Institute of Technology 14 Definition Information/Material in a Form That the CustomerCustomer Is Willing to Pay for Value is DefinedDefined by the Customer Value is CreatedCreated by the Producer 1. Define Value Deborah Nightingale 2002 Massachusetts Institute of Technology 15 Whos the customer? C C useruser C C shareholdershareholder C C environmentalenvironmental C C employeeemployee Whos the Customer? Deborah Nightingale 2002 Massachusetts Institute of Technology 16 The Value Stream Consists of Tasks Required to Bring a Specific Product Through Three Critical Processes: Design - Problem-solving From Concept Through Detailed Design and Engineering to Production Launch Order - Information Management From Order-taking Through Detailed Scheduling to Delivery Make - Physical Transformation from Raw Materials to Finished Product In the Hands Of the Customer C U S T O M E R 2. Identify the Products Value Stream the Actual Product: Component Procurement Supplier: XXX Product: Vehicle Customer: U.S. Government Value: Affordable High Quality High Performance Product On Time Delivery Perform Detail Design J. Wessels 4/27/2001 Rev. 4 - Specs - Environmental Criteria - Standard Parts - Standard Designs - Design Handbook - Geometric Design & Tolerancing - Mfg. Process Capability - Etc. Des. Ref. Library Release BTP Build to Package Buy to Package CDRLs Reports Des.Proc. Guidance - Design for Manufacturing - Design for Assembly - Design to Cost - Design for Key Characteristics - Design for Supportability - Design for 6 Sigma - Design for Define Structural Arrangement Finalize Conceptual Design Conduct Structural Configuration/Cost/Mfg. Trades Perform Airframe Analysis - Weights - Finite Element Model - Environmental Model - Internal Loads - Observability Model Develop Material Allowables Define Arrangement - Production Breaks Develop ICDs Prepare Prelim.Design Develop Layouts Create Assemblies Create Sub-Assemblies Perform Structural Analysis - Stress - Environmental - Weight Production Factory Requirements Analysis Develop Adv. Mfg. Plan Tooling & Mastering Concepts Design Parts & Details Perform Structural Analysis Pre-Contract Reqmnts & Conceptl Des. Component Procurement Spec To All Processes Shown Manage Program Systems Engineering Manage Team Apply Program Plans Apply Technical Plans Apply Processes & Tools Apply Resources Allocate Requirements to Component Allocate Requirements to Structure Prime System Spec Prime Contractor/ Team Process System Reqmts Review Prelim. Design Review Critical Design Review 80% BTP Release zz months yy months 0 months Iterate Test System Development Verification Validation Program Reqmnts SEMP Reqmnts Structure Specs ICDs System Design Review Produce Product Fab Tooling Build & Inspect Deliver Analyze Rework Root Cause Procure Suppliers Build and Assemble Change / Rework Iterate xx months Example: Structural Design Value Stream Map Deborah Nightingale 2002 Massachusetts Institute of Technology 18 2. Piece Where possible 3. Focus on the Product and Its Needs Rather Than the Organization or the Equipment 1. Activities That Are Pure Waste 4. Focus on actual object and never let it out of sight from beginning to completion 5. Ignore traditional boundaries of jobs, careers, functions, and organizations to form a Lean enterprise removing all impediments to the continuous flow of the product 6. Rethink specific work practices and tools to eliminate backflows, scrap, and all stoppages 3. Prefer One Flow Eliminate Flow the Product Deborah Nightingale 2002 Massachusetts Institute of Technology 19 What Is a Value-Added Activity? A value-added activity is any action that transforms information/material into a capability for our ultimate customer at the right time and the right quality. Definition Deborah Nightingale 2002 Massachusetts Institute of Technology 20 Definition Any Activity That Consumes Resources Yet Adds No Value Waste Deborah Nightingale 2002 Massachusetts Institute of Technology 21 Batch Production Example A C D = Different Processes Processing Time = 1Min./ Unit 0 A C D E L A P S E D T I M E M I N Processes - Oriented Layout With Transfer Lot Size of Five 5 A C D 10 A C D 15 A C D 20 A B B D Throughput Time (5 Units) = 5x1 + 5x1 + 5x1 + 5x1 = 20 Min. Work in Process 5 + 5 + 5 + 5 = 20 Units B B B B B C Deborah Nightingale 2002 Massachusetts Institute of Technology 22 Batch Production Example A D = Different Processes Processing Time = 1Min./ Unit 0 A C D E L A P S E D T I M E M I N Processes - Oriented Layout With Transfer Lot Size of Five 5 A C D 10 A C D 15 A C D 20 A B B D Throughput Time (5 Units) = 5x1 + 5x1 + 5x1 + 5x1 = 20 Min. Work in Process 5 + 5 + 5 + 5 = 20 Units C B B B B B C A C 1 A C 2 A C 3 A C 4 A C 5 A C 0 Product-Oriented Layout With Lot Size Of One E L A P S E D T I M E M I N 6 A C 7 A C 8 A C One - Piece Flow Example A C D = Different Processes Processing Time = 1Min./ Unit Throughput Time (5 Units) = 1x4 + 1x1 + 1x1 + 1x1 + 1x1 = 8 Min. Work in Process 1 + 1 + 1 + 1 = 4 Units Deborah Nightingale 2002 Massachusetts Institute of Technology 23 B D B D B D B D B D B D B D B D B D B A C 1 A C 2 A C 3 A C 4 A C 5 A C 0 Product-Oriented Layout With Lot Size Of One E L A P S E D T I M E M I N 6 A C 7 A C 8 A C One - Piece Flow Example A C D = Different Processes Processing Time = 1Min./ Unit Throughput Time (5 Units) = 1x4 + 1x1 + 1x1 + 1x1 + 1x1 = 8 Min. Work in Process 1 + 1 + 1 + 1 = 4 Units Deborah Nightingale 2002 Massachusetts Institute of Technology 24 B D B D B D B D B D B D B D B D B D B Deborah Nightingale 2002 Massachusetts Institute of Technology 25 4. Definition Letting the Customer Pull Value from the Enterprise Dont Make Anything Until It Is Needed Then Make It As Quickly As Possible Pull Deborah Nightingale 2002 Massachusetts Institute of Technology 26 Pull Concept of letting the customer pull product from as needed instead of pushing it on them Reduces inventories and produces one time cash windfall & return on investment Deborah Nightingale 2002 Massachusetts Institute of Technology 27 5. Definition Continuous Process Improvement Pursue Perfection, Not the Competition There Is No End to the Process of Reducing Efforts, Space, Costs and Mistakes Strive for Perfection Deborah Nightingale 2002 Massachusetts Institute of Technology 28 Perfection Continuous radical and incremental improvement Continuous banishment of muda Deborah Nightingale 2002 Massachusetts Institute of Technology 29 Seven Categories of Waste Over Production . Making Ahead of Demand Waiting . Delay From Previous Processing Steps Transportation Unnecessary Transport of Materials Over Processing Doing More Than Is Necessary Inventories . More WIP Than the Absolute Minimum Movement Unnecessary Movement of People During the Course of Their Work Making Defective Products Products Do Not Meet Customer Requirements Some General Product Definition Wastes Task to Be Accomplished (New, In-work, etc.) Undocumented Information Prioritization Too Much Information Inaccurate / Incomplete Information Inadequate Analysis Requirements Creep Change / Multiple Tools Inadequate Testing Generating More Info Than Required Excessive Iterations, Dont Stop at Good Enough Fine Tuning Beyond Required Over Designing Unnecessary Interim Drawings for Build Over Analysis Excessive Test Points Duplicate Tasking Tasks Finished Before Required, e.g. Making Drawings Before They Are Needed Access to Data Storage People Are Not Co-located Walk to Tools (Printer, Copier, CADAM, Etc.) Hand Carry Product for Signatures Travel to Meetings Transferring Data From One Database to Another Physical Movement of Product Unnecessary Movement of Data (Physical or Electron Flows) Required to Stop a Given Task Due to Unavailable, Inaccurate, And/or Late Information Jobs in Queue Waiting for Resources Setup Time (Computer Logon, Printers, Xerox, etc.) Seven Types of Waste Making Ahead of Demand Delay From Previous Processing Steps Unnecessary Transport of Materials Doing More Than Is Necessary More WIP Than the Absolute Minimum Unnecessary Movement of People During the Course of Their Work Products Do Not Meet Customer Requirements Making Defective Products (Rework) Inventories Waiting Movement Transportation Over Processing Over Production Deborah Nightingale 2002 Massachusetts Institute of Technology 30 Exercise Specific Examples You Encounter Seven Types of Waste Making Ahead of Demand Delay From Previous Processing Steps Unnecessary Transport of Materials Doing More Than Is Necessary More WIP Than the Absolute Minimum Unnecessary Movement of People During the Course of Their Work Products Do Not Meet Customer Requirements Making Defective Products (Rework) Inventories Waiting Movement Transportation Over Processing Over Production Deborah Nightingale 2002 Massachusetts Institute of Technology 31 Deborah Nightingale 2002 Massachusetts Institute of Technology 32 Apply Five Simple Principles: Specify value from the standpoint of end customer Identify the value stream for each product family Make the product flow So the customer can pull As you manage toward perfection Deborah Nightingale 2002 Massachusetts Institute of Technology 33 Lean Thinking Differs Sharply from Craft and Mass Production in Important Ways FOCUS CRAFT MASS PRODUCTION LEAN THINKING Focus Task Product Customer Operations Single items Batch and queue Synchronized flow and pull Overall aim Mastery of craft Reduce cost and increase efficiency Reduce waste and add value Quality Integration (part of craft) Inspection (a second stage, after production) Prevention (built in by design & methods) Business strategy Customization Economies of scale and automation Flexibility and adaptability Improvement Master-driven continuous improvement Expert-driven periodic improvement Workforce-dri