Is VDD an Instance of Lean Thinking?

1. Is VDD an Instance of Lean Thinking? Paul Collopy, DFM Consulting AIAA Economics Technical Committee

2. TPS and Optimization Perhaps the most striking difference between mass production and lean production lies in their ultimate objectives. Mass-producers set a limited goal for themselves—“good enough,” which translates into an acceptable number of defects, a maximum acceptable level of inventories, a narrow range of standardized products. To do better, they argue, would cost too much or exceed inherent human capabilities. Lean producers, on the other hand, set their sights explicitly on perfection: continually declining cost, zero defects, and endless product variety. The Machine That Changed the World pp 13-14

3. Value Evaluate Search Design Cycle Attributes Parameters Definition Analysis Including Mass, Performance, and Cost Estimation Configuration VDD and Optimization Decision Creativity

4. TPS and Dealing with Complexity The conventional response has been to deal with the complexities of production scheduling with equally complex forecasting and scheduling systems. TPS compels us to assign supplier-customer roles throughout the production flow. “Customers” are then responsible for obtaining what they need when they need it based upon their own “sales.” As a “supplier,” I am then responsible for mainaining a “store” (supermarket) of my customer’s products, so I can provide them what they want when they need it. Thus, the pull system fights complexity (changing customer orders for models with thousands of variations) with simplicity (as opposed to complex computer systems that generate schedules for every process). John Shook, “Bringing the Toyota Production System to the United States: A Personal Perspective.”

5. Gradient Value Charts for Decentralized Decision Making Partial Derivatives of the Objective Function Engine Inlet Status Value Efficiency 90% 150,000 135,000 Module Design Value is Commensurate with System Design Value Weight 700 -130 -91,000 Reliability 1500 2.3 3,450 x = Maintainability -340 -2,652 7.8 Maintenance Cost 500 -0.5 -250 Support Equipment 12 -15 -180 -1200 Radar Cross-Section 0.1 -120 InfraRed Signature 1.4 -50 -70 Manufacturing Cost 700 -1 -700 Design Value 43,478

6. VDD Distributed Optimal Design Aircraft Systems Wing Design Cockpit Design Propulsion Systems Landing Gear Systems Avionics Systems Turbine Design Propulsion Control System Turbine Blade Heads-Up Servovalve Temperature FADEC Radar Design Design Design Design Sensor Design Display Design

7. TPS and Decision-Making ...a key objective of lean production is to push responsibility far down the organizational ladder. Responsibility means freedom to control one’s work... The Machine That Changed the World p 14

8. Extensive Variables Performance, Cost, and -ilities Composition Function