ROBUST DESIGN & MANUFACTURING APPLICATIONS AT FORD MOTOR COMPANY

1. ROBUST DESIGN & MANUFACTURING APPLICATIONS AT FORD MOTOR COMPANY Dr. Yavuz Goktas Reliability Technical Specialist Ford North American Family Vehicles Quality 1st Industrial Engineering Spring Conferences Izmir Efes Hotel, Izmir, Turkey May 11, 2001

2. PR LS PS1 ST CP J1 SI PH PA CC PS2 KO SC LR Define Characterize Test and Verify Design for Robust Performance Design for Producibility ROBUST ENGINEERING PROCESS-DFSS Vehicle System Sub-system Component

3. Voice of Customer DEFINE Inputs Outputs • HISTORICAL DATA • - Campaign Actions • - Quality History • - Satisfaction Surveys • - Lessons Learned • WANTS DATA • - Customer • - QFD • - Kano Analysis • Regulatory • Requirements • GENERIC DATA • System Design Specification (SDS) & • Worldwide Customer Requirements (WCR) • - Benchmarking Capture the Voice of the Customer • List of Critical to • Satisfaction • Characteristics (CTS’)-Ys • Campaign Prevention Plan • Program Specific SDS • Design Assumptions • High Priority Systems & • Targets

4. System Design Functional Mapping CHARACTERIZE Inputs Outputs • Functional Mapping • VDS/SDS Interfaces • Brainstorming • P-Diagram • D.O.E. • CAE Models • FEA • Real World Usage & Environmental Profile • Generic Design FMEA • Supplier Quality History System Design Functional Mapping • Relate CTS’s (ys) to • CTQs(xs) • System DFMEA • Component DFMEA • Functional Targets • Updated P-Diagram • Noise Factor Management • Strategy • High Impact Supplier List

5. OPTIMIZE-MANUFACTURING Inputs Outputs Design for Producibility • Model Process • (process flowchart) • Process Data • Gage R&R • Process FMEA Generic • Critical to Quality • Characteristics(CTQs-Xs) • Characteristic and • Correlation Matrix • (Ys & Xs) • Process Capability Model • APQP Assessment • - Program PFMEA • - Flow Diagram • - Control Plan • Process Capability for Xs Design for Producibility

6. Design for Robust Performance OPTIMIZE-DESIGN Inputs Outputs Design for Robust Performance • PARAMETER DESIGN • - P-Diagram • D.O.E. • Optimization • TOLERANCE DESIGN • Customer Usage & • Environmental Profiles • Design Verification • Plan • Quantitative • Assessment • Engineering • Specifications

7. Test and Verify VERIFY Inputs Outputs • Engineering Specifications • Design FMEA • Customer Duty Cycle & • Environmental Profiles • Noise Factor Management • Strategy • Design Verification Plan Test and Verify • Design Verification • Plan & Report

8. CRITICAL DESIGN PARAMETERS • COST • QUALITY • TIMING • WEIGHT • PACKAGING

9. COST REDUCTION EFFORTS IN ROBUST ENGINEERING PROCESS CASE STUDY 1: COST REDUCTION & ROBUSTNESS STUDY IN THE DESIGN OF A NEW COMPOSITE NYLON INTAKE MANIFOLD CASE STUDY 2: A 6 SIGMA APPLICATION ON A EUROPEAN VEHICLE LINE FOR NOISE REDUCTION IN THE PASSANGER CABIN

10. COST REDUCTION & ROBUSTNESS STUDY IN THE DESIGN OF A NEW COMPOSITE NYLON INTAKE MANIFOLD

11. OPPORTUNITY DESCRIPTION The conversion of cast aluminum intake manifold to glass-reinforced nylon for COST and WEIGHT improvements has uncovered high frequency radiated noise sources in the air intake system. The objectionable noise was described as hiss noise that can be easily mistaken for engine vacuum leak. The team believes that hiss noise can easily mis-lead dealers for mis-binnings in Warranty which in turn can increase total WARRANTY COST. When no vacuum leak was discovered and the noise was traced to the intake manifold, a cross-functional team was formed to address to resolve this problem. The goal of the team was to identify the causal factors contributing to the hiss noise and concentrate on implementing a robust, financially, technically and timely feasible solution

12. TEAMWORK A cross-functional team was set-up to resolve the intake manifold hiss noise phenomenon.

13. PROCESS IMPROVEMENT METHODS USED

14. PROBLEM RESOLUTION PROCESS FLOW CHART SET-UP TEAM DEVELOP CAUSE & EFFECT DIAGRAM PLAN DOE PERFORM DOE ANALYZE DOE CONFIRM DOE IMPLEMENT DESIGN PERFORM BENCHMARKING

15. CAUSE AND EFFECT DIAGRAM INTAKE MANIFOLD THROTTLE BODY No Tape T-Body Hole Yes Rib Inserts Taped Plenum Surface Texture Nominal Sharp None Sharp T-Body Plenum Thickness Rods Rounded Blended 50% thicker HISS NOISE IACV Location Smooth Direct Remote IACV Channel Surface yes Diffuser Tapered no Yes IACV No Scoop

16. SCREENING DOE The goal of the screening DOE was to identify significant design parameters contributing to intake manifold hiss noise and carry out further robustness studies to recommend design actions to minimize/eliminate hiss noise.

17. FACTORS & LEVELS OF DOE

18. INTAKE MANIFOLD

19. THROTTLE BODY PLATE

20. HONEYCOMB DIFFUSER

21. IACV MOUNT LOCATION

22. T-BODY/SCOOP INSERT/IACV

23. DOE TEST MATRIX

24. QUALITY CHARACTERISTICS 1. Subjective Evaluation A jury of 10 engineers aged between 20 to 50 years old and came from different fields were asked to listen recordings of noise and rate their preferences based on the following table:

25. 2. Objective Evaluation: Overall sound pressure level with a pre-set high frequency bandwith is determined to be an appropriate index to represent hiss noise. Two high frequency bandwiths as 6kHz-16kHz and 8KHz-16KHz were chosen as the noise indices for hiss noise due to strong correlation between subjective and objective measurement of the hiss noise.

26. EXPERIMENT AND DATA ACQUISITION

27. DATA ANALYSIS The significance of the nine main factors on hiss noise was determined statistically by using General Linear Model(GLM) procedure of the statistical package MINITAB. Analysis of Variance and Main Effect plots were utilized to draw conclusions regarding significance of the nine main factors on hiss noise

28. DATA ANALYSIS (continued) ANALYSIS OF VARIANCE: P-Values

29. DATA ANALYSIS (continued) MAIN EFFECTS PLOT: SUBJECTIVE MEASURE Decision Criterion:The bigger-the better

30. DATA ANALYSIS (continued) MAIN EFFECTS PLOT: OBJECTIVE MEASURE (6K-16K Hz) Decision Criterion:The smaller-the better

31. DATA ANALYSIS (continued) MAIN EFFECTS PLOT: OBJECTIVE MEASURE (8K-16K Hz) Decision Criterion:The smaller-the better

32. FOLLOW-UP ROBUSTNESS STUDIES Two full factorial DOEs were conducted on IACV location and T-Body to further study their contribution to the hiss noise. DOE Matrix for IACV Pattern DOE Matrix for Throttle Body Hole

33. CONCLUSION • Statistical analysis using GLM on both subjective and objective • hiss noise measurements concluded with high confidence that • the following factors are significant for hiss noise: • Intake manifold thickness • Throttle Body Hole • IACV Location • The team recommended that the following factor/level settings be • Used to minimize the hiss noise: • 50% thicker Intake manifold- Implemented for 2000 MY • Holes in the Throttle Body - Implemented for 2000 MY • Remote IACV - To be implemented for future program • Honeycomb diffuser - Implemented for 2001 MY

34. RESULTS AN 11 dB(A) IMPROVEMENT IN THE INTAKE MANIFOLD HISS NOISE!!!!!!

35. MAINTAINING THE QUALITY IMPROVEMENT A. Lessons Learned/Awareness • Two presentations given to EDQR during the hiss noise resolution process • A presentation given at PT NVH PAT • The full report of the project is included in the Ford Web at: • http://www.poee.ford.com/VEE/doc/Components/B/Intake/news/intakdoe.html • Published at the ‘99 International SAE Conference (Ref.#: 1999-01-1228) • The team is in the process of submitting the full report of the project to the • Ford technical Journal • Shared the findings of the project with Puma Diesel Engineering

36. B. Benchmarking