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Real Time Cost Impact Assessment of Composite and Metallic Design Alternatives. Dr. Christopher Rush Joe Falque Karen McRitchie. Overview. Introduction Composite Structures – New Challenges Background and Related Research Cost Estimating Challenges, Parametric Cost Modeling
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Real Time Cost Impact Assessment of Composite and Metallic Design Alternatives Dr. Christopher Rush Joe Falque Karen McRitchie
Overview • Introduction • Composite Structures – New Challenges • Background and Related Research • Cost Estimating Challenges, Parametric Cost Modeling • Design for Manufacture and SEER-DFM • SEER-DFM Examples • Analysis of Transmission Servo Piston • Composite and Metallic DFM analysis of SUV Fender • Summary and Conclusions
Objective • Introduce the SEER-DFM cost model methodology for developing composite and metallic cost trade study analyses
Introduction • Composite technology is evolving • Engineers are less familiar with composite structures and processes compared to traditional metallic processes • Presents new set of design and cost modeling challenges • Cost Commitment (see next slide) • Composite Affordability Initiative (CAI) sought to address these issues • SEER-DFM embodies 30 composite processes along side 70 more traditional manufacturing processes • Provides a framework to perform real time cost trade studies
Cost Commitment • 70 - 80 % of product cost is committed during product concept phases • Most cost incurred during production phases • Scope for cost reduction reduces in product phase
Background and Related Research • Cost Estimating Challenges • Limited amount of data during development phases, high uncertainty and expected error • Accounting for technology changes • Requirements to show how cost estimates were derived • risks, assumptions, uncertainty • Estimates need to follow a consistent reliable process
Background and Related Research • Parametric Cost Modeling • Dates back to the 1950’s; • introduced by the RAND Corporation for the US Air Force • widely used by Government and Industry • Uses historical samples to establish relationships • Uses the past to predict the future • Sometimes called Statistical Estimating • Linear regression most popular & simplest technique y = a + b(x) • Typically used during the product development stages • Reduces time required to produce estimates
Background and Related Research • Cost estimating relationship example
Design for Manufacture and SEER-DFM • Design for manufacture (DFM) • Practice of designing with manufacturing in mind • Emphasis on multidisciplinary teams, supersedes sequential product development process
Design for Manufacture and SEER-DFM • Integrated product teams reduce the likelihood of costly engineering changes
Design for Manufacture and SEER-DFM • DFM saves companies money Savings % Respondents
Design for Manufacture and SEER-DFM • Process based parametric cost modeling • Applies the parametric concept to manufacturing processes Finishing Air Gun Spray; Thermal Spray; Electrostatic; Vacuum Metalize; Dip; Chromate/Phosphate; Electrocoat; Electroplate; Brush Electrical Assembly Cable; Harness Mechanical Assembly Fasteners; Riveting/Staking; Gas Flame Welding; Arc, MIG, TIG Welding; Electron Beam Welding; Spot Welding; Brazing; Adhesive Bonding Mold/Cast/Forge Injection Molding; Rotational Molding; Thermoform Molding; Sand Casting; Die Casting; Investment Casting; Forging; Powdered Metals Machining Conventional & High Speed; Milling; Shaping; Turning; Boring; Grinding; Screw Machining; EDMing; Drilling; Reaming; Tapping; Sawing; Broaching; Gear Hobbing; Deburring; Coring Fabrication Shears-Brakes; Punches; CNC Turret; Laser Cut; Gas Flame Cut; Plasma Arc Cut; Dedicated tool & Die; Progressive Die; Spin Forming; Tube Bending; Plate Roll Bending Composites Layup; Filament Winding; Pulltrusion; Composite Spray PC Board Assembly Board Fabrication; PCB Assembly/Solder
Design for Manufacture and SEER-DFM • Extended CAI Processes
Design for Manufacture and SEER-DFM • Process based parametric cost modeling • When integrated with the design process – cost becomes an optimization variable • Perform real time cost trade studies during design process
SEER-DFM Case Studies • DFM Analysis of Transmission Servo Piston • Study goals • Ascertain manufacturing costs • Evaluate tradeoffs using DFM principles • Study began with a rough sketch • Processes modeled using work elements e.g. machining, fabrication, and assembly • Part modeled by creating a work breakdown structure
SEER-DFM Case Studies • Describe major components of transmission servo piston, and their assembly • Describe each component with respect to the people, product, and processes required to manufacture and/or assemble it • Reduce data input with knowledge bases • Pre defined templates of inputs
SEER-DFM Case Studies • Output estimate results using charts and reports • Reports and charts illustrate that most cost is related to machining labor
Option 1 Option 1 - - Option 2 Option 2 - - Option 3 Option 3 - - Machined Machined Die Cast Die Cast Die Cast Die Cast Shaft Shaft Shaft Shaft Shaft / Retainer Shaft / Retainer Material Material $2.3155 $2.3155 $2.3610 $2.3610 $2.3510 $2.3510 Cost/Unit Cost/Unit Total Labor Total Labor Cost/Unit Cost/Unit $4.2944 $4.2944 $3.6463 $3.6463 $3.6316 $3.6316 Tooling Tooling $0.1161 $0.1161 $0.2843 $0.2843 $0.2925 $0.2925 Cost/Unit Cost/Unit Total Total Cost/Unit Cost/Unit $6.7260 $6.7260 $6.2916 $6.2916 $6.2751 $6.2751 SEER-DFM Case Studies • Alert function suggests • consider casting instead of raw stock • reduce part count – consolidate • Change parameter detail inputs for real time cost impact assessment • Including spring retainer as part of the casting = more complex cast, but reduced assembly cost
SEER-DFM Case Studies • Composites and metallic DFM analysis of SUV Fender • Considers 3 options: • Fabrication of steel fender • Fabrication of aluminium fender • Composite manufacture using P4 process and RTM curing • Assumptions • 180,000 production run • Manufacturing labor rate US$100 • Assembly labor rate US$75
SEER-DFM Case Studies • P4 (Programmable Powdered Preform Process) • Developed for automotive • GM use P4 to cost effectively manufacture Silverado truck cargo • Process time 4 minutes
1 1 2 2 3 3 SEER-DFM Case Studies • Spray cut fibres and powdered binder on to a preformed, perforated screen tool • Vacuum and chopper head pressure ensure uniform layup thickness • Hot air is blown through a consolidation tool to melt the powdered binder on the preform • Preform is then ready for resin infusion - RTM
SEER-DFM Case Studies • P4 parameter inputs RTM inputs
SEER-DFM Case Studies • Trade off analysis • P4 process reduces time by 50% • P4 process reduces labor cost by 36% • Reduced material costs • 45% compared to aluminium • 2% compared to steel • Reduced total cost • 42% compared to aluminium • 21% compared to steel • Despite increased P4 tooling cost per unit • Effect on bottom line • Total savings $553,264
SEER-DFM Case Studies • Estimate Probability • All estimates have a degree of uncertainty • Model uncertainty using least, likely, most inputs • Output a range of possibilities for management decisions
Summary and Conclusions • Introduced a process based parametric cost model methodology • Cost model integrates cost as design variable • Perform numerous real time cost impact assessments • Achieve optimum design through informed DFM decisions • Methodology is used to assess cost impact of composite and metallic design options
Contact Details • Christopher Rush • Galorath Incorporated100 N Sepulveda Blvd, Suite 1801El Segundo, CA 90245 • Tel: 310 414 3222 • Email: CRush@Galorath.com • Website: www.galorath.com