1. Dr. Christopher Rush Joe Falque Karen McRitchie
Real Time Cost Impact Assessment of Composite and Metallic Design Alternatives
Dr. Christopher Rush
Joe Falque
Karen McRitchie

2. Overview Introduction Background and Related Research
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

3. Objective
Introduce the SEER-DFM cost model methodology for developing composite and metallic cost trade study analyses

4. 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

5. Cost Commitment
% of product cost is committed during product concept phases
Most cost incurred during production phases
Scope for cost reduction reduces in product phase

6. 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

7. 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

8. Background and Related Research
Cost estimating relationship example

9. 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

10. Design for Manufacture and SEER-DFM
Integrated product teams reduce the likelihood of costly engineering changes

11. Design for Manufacture and SEER-DFM
DFM saves companies money
Savings %
Respondents

12. 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

13. Design for Manufacture and SEER-DFM
Extended CAI Processes

14. 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

15. 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

16. 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

17. SEER-DFM Case Studies Output estimate results using charts and reports
Reports and charts illustrate that most cost is related to machining labor

18. 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
Option 1 -
Machined
Shaft
Option 2
Die Cast
Option 3
Shaft / Retainer
Material
Cost/Unit
$2.3155
$2.3610
$2.3510
Total Labor
$4.2944
$3.6463
$3.6316
Tooling
$0.1161
$0.2843
$0.2925
Total
$6.7260
$6.2916
$6.2751
Including spring retainer as part of the casting = more complex cast, but reduced assembly cost

19. 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

20. 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

21. 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 1 3 2

22. SEER-DFM Case Studies
P4 parameter inputs RTM inputs

23. 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

24. 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

25. 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

26. Contact Details Christopher Rush
Galorath Incorporated 100 N Sepulveda Blvd, Suite 1801 El Segundo, CA 90245
Tel:
Website: