VALUE STREAM MAPPING. Creating a Roadmap for Lean Transformation. Peter L. King. Jennifer S. King

Transcription

1 VALUE STREAM MAPPING PROCESS INDUSTRIES Creating a Roadmap for Lean Transformation Peter L. King Jennifer S. King CRC Press Taylor & Francis Group Boca Raton London New York CRC Press is an imprint of the Taylor & Francis Croup, an informa business A PRODUCTIVITY PRESS BOOK

2 Contents Acknowledgments Introduction xi xiii 1 The Value of Mapping 1 A Focus on Flow Rather Than on Function 2 Summary 4 2 Value Stream Mapping Fundamentals 5 Introduction to Value Stream Mapping 5 Material Flow 7 Major Process Steps 7 Data Boxes 7 Process Box and Process Data Box 8 Inventory Data Box 11 Transportation Data Box 12 Customers Data Box 13 Supplier Data Box 13 Material and Information Flow Icons 14 Information Flow 14 The Third VSM Component The Timeline 18 Parallel Equipment 21 Level of Detail 21 Summary 21 3 VSM Enhancements for Process Operations 25 Distinguishing Features of Process Operations That Require a Different VSM Approach 25 Capital Intensive vs. Labor Intensive 25 Material Flow Patterns SKU Fan Out 26 Product Changeover Issues Are Complex 29 Product Families Selecting a Target Product or Family 30 Takt Rate vs. Takt Time 30 Units of Production 31 v

3 vi Contents Generating the Map 33 Time Units 34 Where to Begin 34 Summary 34 4 Additional Good Mapping Practices 37 Good VSM Practices 37 Map Layout Flow Direction 37 Level of Detail 38 Level of Precision 38 Parallel Equipment 38 Logical Flow vs. Geographie Arrangement 39 Support Processes 41 Computer Tools vs. Brown Paper 44 Qualified Guidance and Coaching 45 Summary 45 5 Our Focusing Problem A Synthetic Fiber Process 47 Process Overview 47 Raw Materials 48 Step 1: Polymerization 48 Step 2: Fiber Spinning 48 Step 3: Draw-Anneal 49 Step 4: Cut Bale 50 Finished Product Storage and Shipping 51 Order Processing and Production Scheduling 51 The Synthetic Fiber Manufacturing VSM 52 6 Developing the Material Flow 55 7 Calculating Data Box Parameters 59 Process Step Data Boxes 59 Overall Equipment Effectiveness (OEE) 60 Calculating Availability 61 Calculating Performance 62 Calculating Quality 62 Calculating OEE 62 Remaining Factors 62 Another Example of OEE 63 Supplier Data Boxes 64 Customer Data Boxes 64 Inventory Data Boxes 65 Transportation Data Boxes 65 Summary 66 8 Material Flow Rates and Takt 67 Calculating Takt 67

4 Contents vii Bales 68 Rope Takt in Gaylords 68 Annealed Product Takt 68 Filament Takt 71 Flake, Spinning, and Polymer Takt 72 Raw Material Takt 72 Summary 72 9 Completing the Data Boxes: Utilization, Delivery Frequency, and Days of Supply 75 Utilization 75 Transportation Frequency 78 Inventory Days of Supply 79 Summary Mapping the Information Flow 83 Why Map Information Flow? 83 Fiber Manufacturing Information Flow 83 Capacity Constraint Resources 84 Additional Information Mapping Tools 88 Summary Developing the Timeline 91 Timeline Principles 91 Fiber VSM Timeline 92 Cash Flow Cycle Time 96 Summary Finding the Waste Analyzing the Map 97 General Impressions from the Current State 98 Inventory Opportunities 98 Baier Reliability 100 Spinning Yield 101 Long Campaign Cycles (EPEIs) 101 Hot Roll Draw-Anneal 101 Uncoordinated Scheduling 101 Capturing Potential Opportunities Scoping the Opportunities 105 Inventory Opportunities Raw Material Inventory in Rail Cars Is Too High Flake Inventory Is High Filament Inventory Is High Rope Finished Product Inventory in Gaylords Is Too High Right Size the Cutter Box Inventory Bale Finished Product Inventory Is Too High 110

5 viii Contents Equipment Opportunities Spinning Changeover Losses Are High; Spinning Utilization Is High Baier Reliability Is Poor Changeover Improvement Baiers Reduce the Baier Campaign Cycle (EPEI) Mothball One Baier Hot Roll Draw-Anneal Reliability and Yield Wastes Mothball One Polymer Reactor 114 System-Wide Opportunities Implement Virtual Cellular Flow Filament Tub FIFOs after Implementation of Virtual Cells Implement Pull Replenishment across the Value Stream Drop the 60 Very Low Demand SKUs 118 Summary Implementation Strategy and Sequence 121 Strategy for Implementation of Improvements 121 Riverside Fiber Plant Future States 122 Future State Generation Future State Generation Future State Generation Summary Future State Value Stream Maps 129 Why a Future State VSM? 129 Future State 1 Map 130 Future State 2 Map 132 Future State 3 Map 134 Summary Supply Chain Mapping 139 Why a Supply Chain Map Is Important 139 Supply Chain Wastes 140 Effects of Wastes at the Supply Chain Level 141 Supply Chain Map Components 142 Future State Supply Chain Map 143 Supply Chain Map Example 144 Summary VSM as a Way of Engaging Employees 149 Origin of the Problem 149 A New Paradigm on the Role of Labor 150 The Nature of Engagement 151 Summary A Roadmap for Continuous Improvement 155 Summary 157

6 Contents ix 19 Benefits of Developing a VSM 159 Operations That Have Benefitted from Using a VSM 159 Processing of Large Rolls in a Sheet Goods Plant 159 Bottling Salad Dressing 162 Cooling Towers in Polyethylene Production 165 Producing Waxes for Coating Cardboard Boxes 165 Improving a Capital Project Execution System 166 Summary 168 Appendix A: Process Industry Characteristics 171 Characteristics That Distinguish the Process Industries 171 Equipment Is Large and Difficult to Relocate 171 Processes Are Difficult to Stop and Restart 172 Capital Intensive vs. Labor Intensive 172 Hidden WIP 173 Product Differentiation Points 173 Summary 174 Appendix B: SMED Principles 177 SMED Origins 177 SMED Concepts 178 Product Changeovers in the Process Industries 179 Summary 179 Appendix C: Cellular Flow 181 Typical Process Plant Equipment Configurations 181 Cellular Manufacturing Applied to Process Lines 183 Summary 186 Appendix D: Pull Replenishment Systems 187 Why Is Pull Important? 187 What Is Pull? 187 Pull in Assembly 188 Difficulties in Process Plants 190 Push-Pull Interface 190 CoriWIP 191 Visual Signals 191 When to Start Pulling: The Sequence of Implementation 194 Value Stream Focus 194 Showing Pull on a Value Stream Map 195 Summary 195 Appendix E: Cycle Stock and Safety Stock 197 Cycle Stock and Safety Stock 197 Calculating Cycle Stock 199 Fixed Interval Replenishment Model 199 Fixed Quantity Replenishment Model 200

7 X Contents Safety Stock 202 Variability in Demand 203 Variability in Lead Time 207 Combined Variability 207 Example Cut-Bale 2 Safety Stock 208 Summary 210 Appendix F: Product Wheels 211 Introduction to Product Wheels 211 Product Wheels Defined 212 Benefits of Product Wheels 214 Product Wheel Applicability 215 Process Improvement Time 216 Summary 216 Appendix G: Additional Reading 217 Index 219 About the Authors 227