Presentation on theme: "ROBUST DESIGN & MANUFACTURING APPLICATIONS AT FORD MOTOR COMPANY Dr. Yavuz Goktas Reliability Technical Specialist Ford North American Family Vehicles."— Presentation transcript:
ROBUST DESIGN & MANUFACTURING APPLICATIONS AT FORD MOTOR COMPANY Dr. Yavuz Goktas Reliability Technical Specialist Ford North American Family Vehicles Quality 1 st Industrial Engineering Spring Conferences Izmir Efes Hotel, Izmir, Turkey May 11, 2001
Define Design for Robust Performance Design for Producibility Characterize Test and Verify PS2 KO SI PS1 SC PHPA PR ST LS LR CC J1CP Component Sub-system System Vehicle ROBUST ENGINEERING PROCESS-DFSS
Capture the Voice of the Customer 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 List of Critical to Satisfaction Characteristics (CTS’)-Ys Campaign Prevention Plan Program Specific SDS Design Assumptions High Priority Systems & Targets Inputs Outputs Voice of Customer DEFINE
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 OutputsInputs System Design 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 CHARACTERIZE
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 Outputs Inputs Design for Producibility OPTIMIZE-MANUFACTURING
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
COST REDUCTION & ROBUSTNESS STUDY IN THE DESIGN OF A NEW COMPOSITE NYLON INTAKE MANIFOLD
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
TEAMWORK A cross-functional team was set-up to resolve the intake manifold hiss noise phenomenon.
PROCESS IMPROVEMENT METHODS USED
PROBLEM RESOLUTION PROCESS FLOW CHART SET-UP TEAM DEVELOP CAUSE & EFFECT DIAGRAM PLAN DOE PERFORM DOE ANALYZE DOE CONFIRM DOE PERFORM BENCHMARKING IMPLEMENT DESIGN
CAUSE AND EFFECT DIAGRAM HISS NOISE INTAKE MANIFOLDTHROTTLE BODY T-Body Hole Taped No Tape T-Body Plenum Sharp Blended Plenum Surface Texture Rods Rounded Sharp IACV Location Direct Remote IACV IACV Channel Surface Smooth Tapered Scoop Yes No Nominal 50% thicker Diffuser yes no Thickness Rib Inserts None Yes
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.
FACTORS & LEVELS OF DOE
THROTTLE BODY PLATE
IACV MOUNT LOCATION
DOE TEST MATRIX
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:
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.
EXPERIMENT AND DATA ACQUISITION
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
DATA ANALYSIS (continued) ANALYSIS OF VARIANCE: P-Values
DATA ANALYSIS (continued) MAIN EFFECTS PLOT: SUBJECTIVE MEASURE Decision Criterion: The bigger-the better
DATA ANALYSIS (continued) MAIN EFFECTS PLOT: OBJECTIVE MEASURE (6K-16K Hz) Decision Criterion: The smaller-the better
DATA ANALYSIS (continued) MAIN EFFECTS PLOT: OBJECTIVE MEASURE (8K-16K Hz) Decision Criterion: The smaller-the better
Two full factorial DOEs were conducted on IACV location and T-Body to further study their contribution to the hiss noise. FOLLOW-UP ROBUSTNESS STUDIES DOE Matrix for Throttle Body HoleDOE Matrix for IACV Pattern
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
RESULTS AN 11 dB(A) IMPROVEMENT IN THE INTAKE MANIFOLD HISS NOISE!!!!!!
MAINTAINING THE QUALITY IMPROVEMENT * 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 A. Lessons Learned/Awareness