Project Management September 16, 2005 James R. Matt Technical Fellow General Motors Corp

Project ManagementSeptember 16, 2005

James R. MattTechnical Fellow

General Motors Corp

“I think there is a world market for maybe five computers.”

-- Thomas Watson, chairman of IBM, 1943

Conventional Wisdom: A Rogue’s Gallery

“There is no reason anyone would want a computer in their home.”

Ken Olson, President, Chairman and Founder of Digital Equipment Corp., 1977

“640K ought to be enough for anybody.”Bill Gates, 1981

“What do 13 people in Seattle know that we don’t?”

Ross Perot when presented with a proposal for EDS to acquire Microsoft, 1980

Conventional Wisdom: A Rogue’s Gallery

“This ‘telephone’ has too many shortcomings to be seriously considered as a means of communication. The device is inherently of no value to us.”

Western union internal memo, 1876.

“The wireless music box has no imaginable commercial value. Who would pay for a message sent to nobody in particular?”

David Sarnoff associates in response to his urgings for investment in the radio in the 1920s.

“The concept is interesting and well-formed, but in order to earn better than a ‘C,’ the idea must be feasible.”

– A Yale University management professor in response to Fred Smith’s paper proposing reliable overnight delivery service. Smith went on to found Federal Express Corp.

Dominant Positions in Business

Who would you have bet on 15 or 20 years ago?• GM or Honda?• GTE or NEC?• Siemens or Hitachi?• Caterpillar or Komatsu?• Philips or Matsushita?• Pan Am or British Airways?

Who would you have bet on 15 or 20 years ago?• GM or Honda?• GTE or NEC?• Siemens or Hitachi?• Caterpillar or Komatsu?• Philips or Matsushita?• Pan Am or British Airways?

Key Thoughts & Simple Tools

Coarse to FineProduct Development

Needs&

Ideas

Organize& Prioritize

SelectProof of Concept

TechnicalSolution

Development

ProductionReadiness

Manufacturing&

Production

Customer and Market Feedback

(data from: Marketing, Sales, Quality, Benchmarking, Customers)

The Force Field Model

TodayState

ImprovedFuture State

ForcesSupporting

Change[Needs]

ForcesResisting Change

[Constraints]

Today’sEquilibrium

The Force Field Model

TodayState

Improved Future State

Increase Forces

SupportingMovement towards

Vision

Minimize Affect of Constraints

Forces ResistingMovement towards Vision

MovementTowards the

Desired Future.

‘Needs’ MapImportance vs: Satisfaction

Importance

High ImportanceHigh Dissatisfaction

HighestPriority

Capture& Work

Low

Low

High

High

(Then, Sort for Easy vs Difficult)

Lack of Satisfaction

Lower ImportanceHigh Dissatisfaction

High ImportanceSatisfied

InsureNo Loss or

Degradation

Low Importance Satisfied

Improve ifEasy andLow Cost

‘Needs’ MapImportance vs: Satisfaction

Importance

High ImportanceHigh Dissatisfaction

HighestPriority

Capture& Work

Low

Low

High

High

(Then, Sort for Easy vs Difficlut)

Lack of Satisfaction

Lower ImportanceHigh Dissatisfaction

High ImportanceAlready Satisfied

InsureNo Loss or

Degradation

Low ImportanceBut also not Satisfied

Improve ifEasy andLow Cost

Insure you are solving the ‘Right’ problem.

Translate ‘Needs’ into Technical Requirements.

Be careful to Prioritize properly based on customer expectations.

Watch out for errors in ‘Trade-off’ decisions.

Clearly Understand “Big Wins”

Spider Chart Performance Targets and Key Wins

Today’s Product or Situation

Best in Class CompetitionTargets for new Design

FasterSpeed

SmallerSize

Durability Life

Spider Chart Performance Targets and Key Wins

Today’s Product or Situation

Best in Class CompetitionTargets for new Design

Key Wins

FasterSpeed

SmallerSize

Durability Life

Break-Out Metrics

Consumer Metrics

“Insider” Technical Metrics

Brand Reputation

Design Feature #### -- Projected Strategic Positioning

Parity Focus Win

Parity Focus Win

Market Positioning for ####

Selling Features

Roadmap ExampleP

rod

uct

Fir

st A

pp

lica

tio

nC

om

pet

itio

nT

ech

no

log

y

Gen 1 Gen 2 Gen 3

2006 GMTXXXPickups

2002Ford

Explorer

2006 GMTQQQ Utilities

200XGMTZZZ

Legend

High Priority

Game Changer

Resourced

IntegratedSubsystem

Controls

IntegratedSubsystem

Controls

IntegratedVehicle

Controls

IntegratedVehicle

ControlsTolerantControls

TolerantControls

Specific Technical Solution - tbd zzzz

2001Mercedes

S500

2004BMW

7 Series

2007

2010 2012

System or Technology – Lifecycle Plan

Per

form

ance

NA97041Suspension Anti-Roll DCSSS

2006 201120092005

NA991190Brakes Dry Interface Corner Brake System

NA991398Suspension RR- IRS Truck W/QS4

NA002186Rear Steer(IRS Compatible)

NA991217Alternative SpringC’ Spring

NA002168Smart Tire (Sensor in Tire)

NA991508Multi-Link Front Suspension,Full Size Trucks

GME991612Steer By Wire

Near-Term

Mid - Term

Long Range

NA991189Steering EPS(High Voltage)

2008

GME991612Steer By Wire

Current Project

Investigation

Not Staffed

Key

Brainstorming

• Creative thinking • Creative is highly non-linear• Synergy - Ideas tend to feed off each other and lead to bigger ideas• Do not rank ideas, or find fault with suggestions at this time• Needs time spent early in project for Creative Thinking

• Creative Capture method• Use Yellow Sticky Notes• Define Categories and repeat process on each

– Write ideas as fast as possible– Limit the time spent, go fast– Review and discuss (do not judge merit just yet)– Consolidate and re-word for concise and clear– Group into patterns

• Set aside as data needed for Project Planning and Risk Management

Fishbone (Ishikawa) Diagram

Man Method

Environment Machine

High Temp

Humidity

Difficult to assemble Not Repeatable

Process

Tends to break down

Sources of error

Set PriorityMap Issues & Enablers

Importance

Urgency

Important, Urgent

Important,Not Yet Urgent

HighPriority

Capture& Work

Low

Low

High

High

(Then, Sort for Easy vs Difficlut)

5 Phase Problem Resolution

1. Problem Definition

2. Containment, Immediate Corrective Action

3. Root Cause

4. Irreversible Corrective Action

5. Verification

Gantt chart – Critical Path Timing

Activities

Define Initial ProjectTask 1Task 2

Etc

Define Requirements

Concept Generation & Selection

Detail Concept

Optimize

1

2

3

4

5

time

Gantt chart – Critical Path Timing

Activities

Define Initial ProjectTask 1Task 2

Etc

Define Requirements

Concept Generation & Selection

Detail Concept

Optimize

1

2

3

4

5

time

The Red Line is the ‘Critical Path’.The Critical Path is the linkage path of tasks in time that if these tasks ‘slip’ the end point of the project duration becomes longer. Tasks on the this timeline are called ‘on the Critical Path’.

Activities are Groups of Tasks that support a Milestone or a key decision point

Milestone is key point in time where certain Activities or Task are planned for completion.

The most important Milestones are often called ‘Gates’ (this example has five Gates in the green diamonds.) Gates are major decision points where the project Key stakeholders approve, redirect, or stop the project.

Decisions from Gates must be clear, the issues and decision documented.

2005 2006 2007 RASIC

J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D R A S

Activities: IDENTIFY

X X XXname name name

DEFINE X X X X X name INVESTIGATE and SYNTHESIZE X X X X X X

DEVELOP and VERIFY X X X X X X X VALIDATION TESTING est.

X X X X X X X X

Resources: Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4Staffing (# people) 0.0 0.0 0.0 2.3 5.7 11.2 15.9 15.5 16.2 4.0 4.0 4.0 RASIC Choices

Veh Center 0.0 0.0 0.0 0.0 1.1 1.1 1.5 1.3 1.5 2.5 2.5 2.5 Bob

Eng Center-Chassis 0.0 0.0 0.0 0.2 1.2 1.5 1.5 1.8 2.3 1.0 1.0 1.0 Eng #1

Eng Center-Electrical 0.0 0.0 0.0 0.0 1.0 1.0 1.2 1.2 1.2 0.5 0.5 0.5 Sue

PE 0.0 0.0 0.0 0.0 0.1 0.2 0.3 0.3 0.3 0.0 0.0 0.0 Mfg Eng

Design 0.0 0.0 0.0 0.0 0.0 0.7 0.7 0.4 0.4 0.0 0.0 0.0 S - Supplier

R&D 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Tom

Powertrain 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Emily

Mfg Center 0.0 0.0 0.0 0.0 0.1 0.2 0.2 0.2 0.2 0.0 0.0 0.0 etc

Supplier (estimated) 0.0 0.0 0.0 2.0 2.0 6.0 10.0 9.8 9.8 0.0 0.0 0.0 etc

Purchasing 0.0 0.0 0.0 0.1 0.2 0.5 0.5 0.5 0.5 0.0 0.0 0.0Avg. Annual Manpower 0.6 12.1 7.1Spending ($K) 0.0 0.0 0.0 0.0 1.1 58.2 24.8 34.4 36.3 0.0 0.0 0.0 NOTE: Cost estimates not real Veh Center 0.0 0.0 0.0 0.0 0.5 26.0 1.5 1.5 1.5 0.0 0.0 0.0 Eng Center-Chassis 0.0 0.0 0.0 0.0 0.0 27.5 14.0 24.0 26.0 0.0 0.0 0.0 Eng Center-Electrical 0.0 0.0 0.0 0.0 0.5 3.0 7.5 7.5 7.5 0.0 0.0 0.0 PE 0.0 0.0 0.0 0.0 0.1 0.2 0.2 0.1 0.1 0.0 0.0 0.0 Design 0.0 0.0 0.0 0.0 0.0 1.4 1.5 1.2 1.2 0.0 0.0 0.0 R&D 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Powertrain 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Mfg Center 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Supplier (paid by GM) 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Purchasing 0.0 0.0 0.0 0.0 0.1 0.1 0.1 0.1 0.1 0.0 0.0 0.0

Total Annual Expenses $0.0K $118.5K $36.3K

Example Gantt Planning & Resources Chart

Trade-off study matrix

Desig

n

Op

tion

#1

Desig

n

Op

tion

#2

Desig

n

Op

tion

#3Example Criteria

Performance

Cost

Mass

Quality

Volume / Size

Risk

Durability

Summation

Key: “++” = Much Better

“+” = Somewhat Better

“0” = No Improvement

“-” = Worse

“ - - ”= Much Worse

Trade-off study matrix

Desig

n

Op

tion

#1

Desig

n

Op

tion

#2

Desig

n

Op

tion

#3Example Criteria

Performance

Cost

Mass

Quality

Volume / Size

Risk

Durability

++

++

++

++- -

- -

0

-

+

+

0

-

+

+

+

+

0

0

0

++

-

Summation +1 +5 +3

Key: “++” = Much Better

“+” = Somewhat Better

“0” = No Improvement

“-” = Worse

“ - - ”= Much Worse

‘Risk’

Types of Risk (things gone ‘wrong’, or critical items not going ‘right’)

• Business• Timing• Technical

Quantify Relative Risk

Risk f(L,M) = (Likelihood) X (Magnitude)

Method1. Brainstorm Potential Problems2. Define Likelihood of Occurrence (1 -10 scale)3. Define Magnitude should problem occur (1-10 scale)4. (Risk Priority Number) RPN = (Likelihood) X (Magnitude)5. Rank order into a bar chart (Pareto Diagram)6. Define Countermeasures

Pareto Diagram

RPN(Risk

PriorityNumber)

Specific Potential Problems

Focus on the high RPN Risk items and put in place Countermeasures

Must Insure --‘Bang for the Buck’(limited resources cause the need to Focus)

Lower

Higher

Team Work Breakdown Structure

Team Leader

Simulation

Design

Procurement & Cost Estimation

Recorder& Scheduling

Research

Requirements,Specifications

Planning& Timing

Trade-Off Study

CustomerContact

Results Documentation

Gate ReviewPreparation

Open IssueManagement

BalanceWork Load

PrototypeTest

PrototypeBuild


Build & ToolingAvailability

Roles and responsibilities can and should be shared, moved and adjusted to assure a fair balance and to handle spikes in work.

Metrics should be set up to monitor the quality and timely delivery of work elements

Monitor and assess

Progress

Gather Metrics

Five Person Team


Team Leader

Simulation

Design



Research


Planning& Timing

Trade-Off Study

CustomerContact




BalanceWork Load

PrototypeTest

PrototypeBuild



Monitor and assess

Progress

Gather Metrics

Four Person Team


Team Leader

Simulation

Design



Research


Planning& Timing

Trade-Off Study

CustomerContact




BalanceWork Load

PrototypeTest

PrototypeBuild



Monitor and assess

Progress

Gather Metrics

Three Person Team

Engineering Project Management

Coarse to FineProduct Development

Needs&

Ideas

Organize& Prioritize

SelectProof of Concept

TechnicalSolution

Development

ProductionReadiness

Manufacturing&

Production

Customer and Market Feedback

(data from: Marketing, Sales, Quality, Benchmarking, Customers)

Technical Solution Level Indication of Risk and Time needed to bring to Market.

1

2

3

4

5

Production: Known, Proven, in Production, Refinement of existing.

Verification: Known, Proven, in Competitive Production, ‘Tribal Knowledge’ exists Needs Verification to specific Requirements.

Development: Known, Proven, Needs modification to meet requirements.

Feasibility: Known, Not Proven, Concept Demonstrated, No Production Applications, Needs Significant Engineering Design/Analysis/Development.

Idea: Unknown, Invention required, Understand Market Pull, Need Technical Direction, Need Technical Solution, Optimal Solution Unknown.

Phase 00Phase 00Define

Requirements, Key Interfaces,& Constraints

Concepts Generate Detail

Concept

Product Development

Approve ProjectPlan, Team, and & Deliverables

RequirementsAgreement

Select & Approve Design

Concept

1 2

ApproveDetail Concept

43

Optimize &

Verify

ApproveConcept

Verification

5

Technology Planning

Determine Needs, Select Projects.& Assign Teams

I - IdentifyD1

Define Requirements

D2 – Design Concept

O - Optimize

V - Verify

DFSS ‘ IDDOV & Product Development

Design for Six Sigma IDDOV

Phase 00Phase 00Define

Requirements, Key Interfaces,& Constraints

Product Development

Approve ProjectPlan, Team, and

& Deliverables

1 2 43 5

Technology Planning

Determine Needs, Select Projects.& Assign Teams

Project Tasks and Gate Reviews

Tasks:•Determine Perf & Manf Requirements

•Define Business Targets

•Define Needs

•

Review with key Stakeholders

•

Develop Commercial Approach

•

Define Project Plan & Resources Required

Tasks:

•Establish Project Plan

•Obtain Lessons Learned

•Draft Initial Specifications

•Define Interfaces, Constraints

•Gather Information todetermine Requirements

•Conduct Gate Review #1

Tasks:•Generate & Assess Alternative concepts

•Perform Evaluations

•Concept Tradeoff Study

•Refine Specifications & Robust Eng Plan (DOE)

•Conduct Concept Reviewand Approve Design Concept

Tasks:•Develop purchasing info

•Conduct Robust assessment•Optimize Concepts

•Conduct Peer Review

•Update all Business, Technical, and Project Documents

•Approve Details ConceptMake Purchasing Decisions

Tasks:•Develop Design

•Finalize Development &Test Plan

•Construct, Build, and Test Prototype

•Verify Hardware, Softwareto Technical Requirements

Conduct Final DesignReview

•Update all Business & Technical Documents

Define Requirements Key Interfaces & Constraints

Concept Generation & Design Selection

Robust Assessment & Purchasing

Optimize & ValidateDefine Initial Project

•

RequirementsAgreement

Select & Approve Design

Concept

ApproveDetail Concept

ApproveConcept

Verification

Concepts Generate Detail

Concept

Optimize &

Verify

Five Objectives of Every Gate Review

1) Explain the Benefits of the Technical Solution or Technology

2) Show the Technical Feasibility of approach and solution

3) Show the Balance of Performance to Business Imperatives

4) Explain the Risks:a) Business.b) Application Timing.c) Technical.

5) Explain the Expected Engineering Expenses & Costs.

Five Objectives of Every Design Project Review

1) Explain the Benefits of the Technical Solution or Technology

2) Show the Technical Feasibility of approach and solution

3) Show the Balance of Performance to Business Imperatives

4) Explain the Risks:(& Risk Mgt Plan, Consider Risk of doing or Not doing)

a) Business.b) Application Timing.c) Technical.

5) Explain the Expected Engineering Expenses & Costs.(Required vs: Available -- Manpower, Materials,…)

Define what can, (should, is) being done to Reduce the Risk!

(& how alternatives ‘Stack up’ and why we should do one approach or another)

ExampleUpper Strut Mount

Design For Six Sigma Example

Performance

Variation

Robust Design to ‘Band-width’

Design BDesign A

Operating Conditions

What is the ‘Better’ Design, A or B?

Define the Basic Functions

• Brainstorm a list of Basic Functions the Product must provide. “What does this thing need to do?”– Use Verbs:

• React• Position• Isolate• Filter• Rotate• Limit• Amplify• etc

Orient & Position

Stays in place over life (loaded position, dynamic & static)

Stays in place during suspension travel

Positions correctly at initial assembly

Service orientation (ex: side-load compensation)

Isolate

Quiet over life (no undesired contacts: metal to metal, contacts – click/clank, no rubber to rubber/metal relative motion - squeak,

Maintains desired Rate curves (over life, throughout travels, dynamic frequency)

Must have mating part stiffness/mobility

React & Distribute Loads

Limit Wheel Travel

Impact Forces (limit Doming of shock tower)

Maintain Suspension Geometry - React Suspension Forces (Camber, Jounce, Rebound, Spring Side Loads)

Spring, Strut Rod, Jounce Bumper – all to Body

Brake Force Reaction

Allow Rotation & Coning while steering

Low Friction

Smooth & Quiet

Low Hysterisis

Sufficient Coning Clearance & Compliance

Limit Travels

Design Travel Objective not violated (specifically: MEJ, Rebound)

Facilitate Assembly

Avoids Mis-Builds, or difficult Builds (provisions for alignment, operator adis, no interferences, retention adequate, GD&T adequate)

Tune-ability

Wide range of linear axial rates

Independently tune axial to radial rate

Volume of Rubber (shape of rate curve, and dynamic isolation)

Amount of axial pre-load (linearity, amount of linear range, rate build up)

Functions

Orient & PositionStays in place over life (loaded position, dynamic & static)




IsolateQuiet over life (no undesired contacts: metal to metal, contacts – click/clank, no rubber to rubber/metal relative motion - squeak, Maintains desired Rate curves (over life, throughout travels, dynamic frequency)


React & Distribute Loads

Limit Wheel Travel

Impact Forces (limit Doming of shock tower)Maintain Suspension Geometry - React Suspension Forces (Camber, Jounce, Rebound, Spring Side Loads), Spring, Strut Rod, Jounce Bumper – all to Body

Brake Force Reaction

Allow Rotation & Coning while steering

Low Bearing Friction

Smooth & Quiet

Low Rubber Hysterisis

Sufficient Coning Clearance & Compliance

Limit TravelsDesign Travel Objective not violated (specifically: MEJ, Rebound)

Facilitate AssemblyAvoids Mis-Builds, or difficult Builds (provisions for alignment, operator adis, no interferences, retention

Tune-ability

Wide range of linear axial rates

Independently tune axial to radial rateVolume of Rubber (shape of rate curve, and dynamic isolation)Amount of axial pre-load (linearity, amount of linear range, rate build up)

Consider Classis Failure Mechanism that Cause Failure Modes

• Creep (relaxation and flow over time, plastic movement, often accelerated with heat or high loads)

• Fracture (brittle failure due to sudden physical overload, cracking)• Yield (Tensile or bending failure, permanent deformation)• Physio-Chemical Instability (Chemical change in material

properties, Corrosion, UV instability, chemical attack of solvent or lubricants, heat aging of rubber)

• Dimensional Incompatibility (Stack up of tolerances, mis-positioning, flexing of base or bracket, too big, too small)

• Contamination (dirt, grit, dust, mixed materials)• Vibration and Mechanical Shock (mechanical or electrical

high frequency, surge, sudden overload)• Environmental (hot, cold, humid, submersion)• Wear (repeated cyclic load causing material removal)

Matrix Functions vs Failure Mechanisms – Evaluate Risk due to Sensitivities

Cre

ep

Frac

ture

Yie

ld

Phy

sio

-Che

mic

al In

stab

ility

Dim

ensi

onal

Inco

mpa

tibili

ty

Con

tam

inat

ion

Vib

ratio

n an

d M

echa

nica

l Sho

ck

Env

iron

men

tal

Wea

r

React

Position

Isolate

Filter

Rotate

Limit

Amplify

Functions

Failure Mechanisms

Matrix Functions vs Failure Mechanisms – Evaluate Risk due to Sensitivities

Cre

ep

Frac

ture

Yie

ld

Phy

sio

-Che

mic

al In

stab

ility

Dim

ensi

onal

Inco

mpa

tibili

ty

Con

tam

inat

ion

Vib

ratio

n an

d M

echa

nica

l Sho

ck

Env

iron

men

tal

Wea

r

React

Position

Isolate

Filter

Rotate

Limit

Amplify

High

High

High

High

Med

Med

Matrix Assessment – Knowledge Gathering

Noise Factors

Functions:Position,Isolate,

React Loads

Energy

In OutDesired Functional Characteristic

Left to right -- The Forward PassEvaluate the Primary Functions and the Likelihood of the Failure Mechanisms allowing a weakness in the product design to manifest as a loss in the Desired Functional Characteristic.

Think of loss due to Noise Factors as a Signal to Noise ratio.If energy is lost in the system, then the Signal to Noise ratio must not be Unity. Attack the sensitivity of the design to the probable Noise Factors that are likely to degrade the performance.

A ‘Robust’ design is insensitive to Noise

The Forward Pass

Position

Stays in place over life

Tolerant of misaligned mating parts

Isolate

Quiet over life

Noise Transmission is good

React Loads

Rate Curve is within Bandwidth

Structure handles load with out excessive Damage

(Failure Mechanisms cause Failure Modes)Environment

ContaminationYield

FatigueFracture

Vibration / Mechanical ShockWear

Electrical / Software CompatibilityPhysio-Chemical Instability

CreepDimensional Incompatibility

DFSS - Front Upper Strut Mount

Noise Factors


React Loads

Energy Desired Functional Characteristic

Noise Factors


React Loads

Energy Primary Function

The Forward Pass

Position

Isolate

React Loads

Fai

lure

Mec

han

ism

s E

nvi

ron

men

tC

onta

min

atio

nY

ield

Fra

ctu

reV

ibra

tion

/ M

ech

anic

al S

hoc

kW

ear

Ele

ctri

cal /

Sof

twar

eP

hys

io-C

hem

ical

In

stab

ilit

yC

reep

Dim

ensi

onal

In

com

pat

ibil

ity

Primary Functions

Likelihood of Primary Function being affected by a specific Failure Mechanism

Likelihood: of compromise of a “Primary Function” due to a Sensitivity to “Failure Mechanism”.Strong Likelihood = “ + ”Neutral = “ 0 ”Not Sensitive = “ – ”


React Loads

Anticipated or

Historic Problems

The Reverse Pass learn for what has happened before

Historic – ‘Things Gone Wrong’Risk concerns based on Historical Failures Applications Corrective Action

Greater deflection than planned, In bearing seal (clam shelling), allowed contamination. Lead to wear, roughness, and noise.

Increase metal thickness (stiffness), added lip seals, anti-corrosion race way, orient bearing to spring axis. Large bearing diameter allowed large clam shelling -

Lack of bearing retention resulting in displacement due to side loading

corrective action: add location features to locate and retain bearing.

Material Handling forces cause bearings to separate and balls fall out.

Add, extend snap fit tabs to keep balls in place during handling for robustness.

Fatigue life of rubber after vehicle durability test, EOL tearing

Rubber compound not as strong for new supplier. Decrease stress by Increasing rubber thickness, add volume. And changed shape.

As Loaded position of mount was not comprehended in design, redesign to offset strut rod to allow proper position at curb height.

Need to know loading position as accurate as possible, and change in load from vehicle to vehicle.

Tick noise on mount. Plastic retainer cup. Stick/slip/slapping caused a Teflon washer to be added. Click due to hard jounce bumper cup to striker plate and strut mount, on excessive coning.

Jounce bumper cup interface integrated into top mount.

Retention of jounce bumper and dust tube inadequate (rod hugger) allowed dust tube to slide down and expose rod. Corrosion of rod due to exposure. Could also cause noise.

Positive retention of dust boot and jounce bumper to strut mount, avoid rod hugger (snap fit, fastener, clamp, etc).

Long Jounce bumpers with dust boot attached to tip of jounce bumper (with large deflections) can allow dust boot to slide off at extremes of travel.


React Loads

Anticipated or

Historic Problems

The Reverse Pass learn for what has happened before

Link Historic Problems to Failure MechanismsEnvironment

ContaminationYield

FatigueFracture

Vibration / Mechanical ShockWear

Electrical / Software CompatibilityPhysio-Chemical Instability

CreepDimensional Incompatibility

Noise Factors


React Loads

Anticipated Problems

The Reverse Pass

Noise at the end of life

Loss of attachment

Bearing Drag

Non-linear road feel

Fai

lure

Mec

han

ism

s E

nvi

ron

men

tC

onta

min

atio

nY

ield

Fra

ctu

reV

ibra

tion

/ M

ech

anic

al S

hoc

kW

ear

Ele

ctri

cal /

Sof

twar

eP

hys

io-C

hem

ical

In

stab

ilit

yC

reep

Dim

ensi

onal

In

com

pat

ibil

ity

Historic and anticipated Problems

Linkage of Failure Mechanisms to Anticipated Problems

Failure Mechanism ‘Link’ to Problem :Strong Link = “ + ”Moderate / Not Sure = “ 0 ”Not Linked = “ – ”

Now think in terms of the design Components (and for competing design options)

A – Inner Metal B – Primary/Shear IsolatorC – Upper Rate WasherD – Reaction WasherE – Reaction IsolatorF – Outer/Compression IsolatorG – Main StampingH – Lower Rate Washer

A

B

C

D E

F

G

H

Orient & Position

Stays in place over life (loaded position, dynamic & static)




Isolate

Quiet over life (no undesired contacts: metal to metal, contacts – click/clank, no rubber to rubber/metal relative motion - squeak,

Maintains desired Rate curves (over life, throughout travels, dynamic frequency)


React Loads

Rate Curve is within Bandwidth

Structure handles load with out excessive Damage

Design For Six Sigma - Front Upper Strut Mount

Transfer FunctionEnergy

Desired Functional Characteristic

Define1)Measurement Strategy for Desired Functional Characteristics, 2) using Failure Mechanisms as Noise Factors, 3) consider the components involved for various design Concepts

Components:Spring SeatInner MetalPrimary IsolatorMain StampingOuter Compression RubberIn-Molded Metal StampingUpper Rate WasherLower Rate WasherBearingTop Reaction WasherNuts (2)Jounce Bumper CupJounce BumperDust Boot

Noise Factors

Chart the probability of each Failure Mechanism contributing to historic problems and loss of desired Functions

Failure Mechanisms Environment

ContaminationYield

Fracture Vibration / Mechanical Shock

WearElectrical / Software

Physio-Chemical InstabilityCreep

Dimensional Incompatibility

In this case, Contamination, Yield, Wear, and Dimensional Incompatibility are the high Occurrence Failure Mechanism that are anticipated as the dominate Noise factors.


React Loads

EnergyDesired Functional Characteristic

Anticipated Problems

Forward Pass

Reverse Pass

Top Mount Bearing

Create a DOE:•Consult with a DOE expert •Set up a Component Development Test •Look for sensitivity at the end of life for Failure Mechanisms: Contamination, Physio-Chemical Instability, and Dimensional Incompatibility

Failure Mechanisms Contamination

WearPhysio-Chemical Instability


Pos

itio

n

Isol

ate

Rea

ct L

oad

s

Noi

se a

t th

e en

d o

f li

fe

Los

s of

att

ach

men

t

Bea

rin

g D

rag

Non

-lin

ear

road

fee

l

X

X

X

XX X

DOE:•Partial Factorial Matrix experiment

•Expert Knowledge, seek help in creation•Garbage in Garbage out (usually due to bad assumptions)

•Want a simple lab fixture(s) to run a fast DOE to understand design sensitivity to Noise factors.•Run carefully Created samples to test for interactions

Failure Mechanisms Contamination

WearPhysio-Chemical Instability


Pos

itio

n

Isol

ate

Rea

ct L

oad

s

Noi

se a

t th

e en

d o

f li

fe

Los

s of

att

ach

men

t

Bea

rin

g D

rag

Non

-lin

ear

road

fee

l

X

X

X

XX X

ExampleMultifunction Headlamp Switch

HeadlampOn / Off

HeadlampHigh / Low

Turn Signal

Cruise ControlSet, On, Off

Customer Electrical Control

Component test plan was designed to test each function

as independent variables

All part passed the lab test without incident

Functions


HeadlampOn / Off

HeadlampHigh / Low

Turn Signal



However:Mechanical Interaction Inside theMultifunction Switch caused the

headlamp contact carrier to slightly rock when the Turn Signal was used.

This caused a voltage spike and high resistance path and heat in the switch.

Functions


HeadlampOn / Off

HeadlampHigh / Low

Turn Signal



DOE factors for test matrix1) Type of Lubricant in the switch2) Contact Material 3) Contact Plating4) Spring Pressure

The optimal combination was found and the design was quickly changed.No field issues were found

Basic Principles – Friction, transient loads, moments, unforeseen interactions, manufacturing processes and true capabilities, marginally stable systems, static electricity, grounding

Wrong Assumptions (independence of functions in switch example)

Lack of parts available on time

Components cost more than estimated

Stack up of tolerances – reality is not design nominal

Murphy’s Law, Chaos Theory, probability and statistical theory at work

False or unachievable accuracy – How close is close enough or what can you actually obtain in the real world

Causes of Problems

Set up a good project plan with Milestones and Gate Reviews

Clearly defined Deliverables

Set up a budget (with a 10% contingency) and obtain good cost estimates and availability of materials, manpower, and facilities

Front Load your efforts – get off to a good start

Assign tasks to team members based on skill sets and personal preferences

Make progress visible, create a temporary War Room Wall and require that team members post their progress

Use Standard parts and commonly available materials - Do not invent what is already available. Focus invention on what does not already exist and yet is essential to the project.

Do your homeworktake time to study and learn as much as you can about the basic principles involved, what has

been done before, what has been written, what is the current State of the Art.Benchmarking – what is the competition doing? Brainstorm Alternatives – do not jump to the answer Allow for Experimentation – this takes twice as long as you think.Expect that ‘Things will not work right the first time’ – allow recovery time (Slack Time)

Ideas to Help