Failure Mode and Effects Analysis

FMEA HistoryFMEA HistoryThis This “type” “type” of thinking has been around of thinking has been around for hundreds of years. It was first for hundreds of years. It was first formalized in the aerospace industry formalized in the aerospace industry during the Apollo program in the 1960’s.during the Apollo program in the 1960’s.

Initial automotive adoption in the 1970’s.Initial automotive adoption in the 1970’s.

Potential serious & frequent safety issues.Potential serious & frequent safety issues.

Required by QS-9000 & Advanced Product Quality Planning Process Required by QS-9000 & Advanced Product Quality Planning Process in 1994.in 1994.

Now adopted by many other industries.Now adopted by many other industries.

For all automotive suppliers.For all automotive suppliers.

Potential serious & frequent safety issues or loyalty issues.Potential serious & frequent safety issues or loyalty issues.

FMEA -- An Introduction

• Why Do FMEAs?

• Definition, Purpose, Types, Benefits

• FMEA Working Model

• Generating / Managing

• Team Approach

Day 1Day 1

IntroductionIntroduction

FMEA -- Definition

• Recognize and evaluate the potential failure of a product or process and its effects

• Identify actions which could eliminate or reduce the chance of the potential failure occurring

• Document the process

2-2

Structured group of activities which ...

FMEA PurposesFa

ilure

s

Time

Elimination ofFailures

JOB 1

Origin ofFailures

FMEA

• Identify potential failure modes and rate severity of effects

• Identify critical and significant characteristics

• Help engineers prioritize and focus on eliminating product and process concerns and helps prevent problems from occurring

• Test adequacy of controls from DCP process

FMEA -- Purposes

2-2

FMEAs are intended to ...

FMEA -- Types

2-4

ConceptFMEA

ConceptFMEA Component

DesignFMEA

DesignFMEA

System

Sub-System

ProcessFMEA

ProcessFMEA

Assembly

Manufacturing

System

Component

Sub-System

System

Component

Sub-System

Benefits -- Concept FMEAs

• Helps select optimum concept• Identifies potential failure modes• Considers potential effects• Helps generate occurrence ratings• Identifies testing requirements• Helps determine if hardware system

redundancy is required

2-5

Design

Process

ConceptConcept

Benefits -- Design FMEAs

• Aids in evaluating requirements and alternatives

• Aids in initial design for DFM

• Increases probability of detecting failure modes and their effects

• Provides additional information for testing requirements

• Helps identify critical and significant characteristics

• Helps validate DVPs and SDSs

2-5

Process

Concept

DesignDesign

Benefits -- Process FMEAs

• Identifies potential product related failure modes

• Assesses effects on all customers• Identifies potential Manufacturing and

Assembly causes to focus controls on reducing occurrence and/or increasing detection

• Establishes a priority system for considering corrective actions

• Identifies confirmed critical and significant characteristics

2-6

Design

Concept

ProcessProcess

Generating FMEAs

FMEAs

Who initiates?Who initiates?

2-9

Failure Mode and

Effects Analysis

Failure Mode and

Effects Analysis

Who prepares?Who prepares? Who updates?Who updates?

Who is FMEA customer?

Who is FMEA customer?

When started and updated?

When started and updated?

Relationshipto FPDS?

Relationshipto FPDS?

When is FMEA complete?

When is FMEA complete?

How is FMEA documented?

How is FMEA documented?

When to discard?

When to discard?

___ System___ Subsystem___ ComponentModel Year / Vehicle(s):Core Team:

PotentialFailure Mode and Effects Analysis

Design Responsibility:Key Date:

FMEA Number:Page 1 of 1Prepared by:FMEA Date ( Orig): (Rev)

Action ResultsPotentialFailureMode

PotentialEffect(s)

of Failure

Sev

Class

PotentialCause(s)/

MechanismsFailure

Occur

CurrentDesign

Controls

Detec

RPN

RecommendedAction(s)

Responsibility &Target

Completion DateActionsTaken

Sev

Occ

Det

RPN

Item

Function

FMEA Working Model

Managing FMEAs

• Modification to a component, process or system is planned

• Component is to be used in new environment

• Customer concern arises: Global 8D

FMEAs are living documents, and are updated when ...

FMEAs and Systems Engineering

2-13

Vehicle Level Inputs• Purchaser / owner / operator• Regulatory (FMVSS, EPA, ...)• Corporate (WCR, ABS, Manuf, ...)

Vehicle Level Requirements• Vehicle Attributes• Vehicle System Specification - VDS

System / Subsystem Level• System &• Subsystem Design Specifications -

SDS

Part/Component Design

Part /Component Fabrication /

Verification

SystemVerification

Purchase, Operate& Maintain

VehicleVerification

Disposal

Customer Focus

Customer Experience & Feedback

Customer

DVM / DVP Production

RequirementsCascade

RequirementsCascade

RequirementsCascade

FeasibilityFeedback

DVM / DVP

FeasibilityFeedback

FeasibilityFeedback

Requirements

CustomerMusts / Wants

CustomerSatisfaction

Component Design Specification - CDS

CFMEA

DFMEA

PFMEA

•

KO SI SC PA PR J1

CoreTeam

Team Approach -- FMEA

SupportTeam

3-5

Design FMEA -- An Introduction

Identify FMEA Team

Establish Scope

Describe Function

» Brainstorming

» Function Trees

Practice Exercise 1

Day 1Day 1

Design FMEA Design FMEA IntroductionIntroduction

___ System___ Subsystem___ ComponentModel Year / Vehicle(s):Core Team:

PotentialFailure Mode and Effects Analysis

Design Responsibility:Key Date:

FMEA Number:Page 1 of 1Prepared by:FMEA Date ( Orig): (Rev)

Action ResultsPotentialFailureMode

PotentialEffect(s)

of Failure

Sev

Class

PotentialCause(s)/

MechanismsFailure

Occur

CurrentDesign

Controls

Detec

RPN

RecommendedAction(s)

Responsibility &Target

Completion DateActionsTaken

Sev

Occ

Det

RPN

Item

Function

Design FMEA

Team

ScopeTeam

Design FMEA -- Team

Design Engineer

Manufacturing / Process Engineer

CORETeam

Representatives from:

• Customer Service

• Suppliers

• Global Test Operations

• Corporate Quality

Support

Team

Facilitator or Application Engineer

Technical Affairs

3-5

Design FMEA -- Scope

• Create a block diagram

• Identify the boundary for analysis

• Confirm composition of the support team

Once core team is established...

3-8

Constructing Block Diagrams

Component/Assembly

Adhesive

Screw WeldPart X

Part Y

Part Z

Service

OtherSystems

Assembly

User

3-10

Block Diagram -- Example

Headlamp Assembly

Block Diagram -- Example

Vertical Trimmer Assembly

Block Diagram -- Example

VerticalTrimmer

Assembly

ReflectorVehicle BodyUpper Cross

Member

Hood(Clearance)

AdjusterSocket

User

Lateral Location

ScrewClips

2

___ System___ Subsystem___ ComponentModel Year / Vehicle(s):Core Team:

PotentialFailure Mode and Effects Analysis

Design Responsibility:Key Date:

FMEA Number:Page 1 of 1Prepared by:FMEA Date ( Orig): (Rev)

Action ResultsPotentialFailureMode

PotentialEffect(s)

of Failure

Sev

Class

PotentialCause(s)/

MechanismsFailure

Occur

CurrentDesign

Controls

Detec

RPN

RecommendedAction(s)

Responsibility &Target

Completion DateActionsTaken

Sev

Occ

Det

RPN

Item

Function

Determine Function

Team

Scope

What is Function ?

• Design intent or engineering requirement

• Must be measurable or set at an actionable level

• Representation of all wants, needs and requirements, both spoken and unspoken

5-6

VerbVerb

Indicates action, occurrence, being

Generate

ControlDispense

Prevent Retain

NounNoun

Indicates what the action relates to

Describe Function

5-7

LightSpeedFuelSeat TrackRust

Describe Function

Thought Starters ...• Satisfy user

• Attract user

• Assure convenience

• Assure dependability

• Governmental requirements

• Safety requirements

Brainstorming

Exercise in creative thinking

Method to generate ideas

Brainstorming -- Guidelines

• Warm up

• Suspend judgment

• Anything goes

• Quantity counts

• Springboard

• Persevere

• Warm down

Brainstorming -- Pitfalls

• Low team trust

• Broad task definition

• Criticism, competition, defensiveness

• Silliness, lack of focus

• Questions and explanations

• Organizing ideas during creative stage

Brainstorming -- Agreement

• Everyone explains view(s)

• Identify needs of individuals

• If you can’t meet a need, say so

• Check out feelings -- yours / others

• Don’t compromise, average, or ‘split the difference’

Function Trees

• Provide an organized approach to identify the essential features of a product (or process sometimes)

• Help ensure that ‘unspoken’ and ‘spoken’ requirements are defined

• Provide a graphical representation of functions to ensure clear, total team understanding

Primary Level

SecondaryLevel

Constructing Function Trees

TertiaryLevel

HOW ? WHY ?

AdjustHeadlamp

Vertical Trimmer Function Tree

HOW ?

Permit / Maintain HorizontalAdjustment

Permit / Maintain Vertical Adjustment

Retain Setting 10 Years, 150,000 Miles

Retain Setting 10 Years, 150,000 Miles

Adjust Light Beam XBoth Directions

Locate Headlamp Laterally 10 Years, 150,000 Miles

Adjust Light Beam XBoth Directions

Locate Headlamp Vertically 10 Years, 150,000 Miles

WHY ?

Guidelines

• Brainstorm all functions (VERB - NOUN)

• Document individual functions by asking “HOW is function achieved?”

• Repeat left to right, until actionable level

• Use worksheet to check that actionable level is measurable

• Work right to left and check structure by asking “WHY is function included?”

Practice Exercise 1

Block diagram Brainstorming Function Tree

Presentation -- Practice 1

TechnicTechnical al

DebriefDebrief

TechnicTechnical al

DebriefDebrief

Team Team DebriefDebriefTeam Team

DebriefDebrief

Design FMEA Functions

___ System___ Subsystem___ ComponentModel Year / Vehicle(s):Core Team:

PotentialFailure Mode and Effects Analysis

Design Responsibility:Key Date:

FMEA Number:Page 1 of 1Prepared by:FMEA Date ( Orig): (Rev)

Action ResultsPotentialFailureMode

PotentialEffect(s)

of Failure

Sev

Class

PotentialCause(s)/

MechanismsFailure

Occur

CurrentDesign

Controls

Detec

RPN

RecommendedAction(s)

Responsibility &Target

Completion DateActionsTaken

Sev

Occ

Det

RPN

Item

Function

Function 3

Function n

Function 2

Function 1

Function

Sub-Function

Sub-Function

Sub-Function

Sub-Sub-Function

Sub-Sub-Function

Sub-Sub-Function

Design FMEA Path 1

Day 1Day 1

DFMEA -- Path DFMEA -- Path 11

Failure Modes

Effects -- Severity

Recommended Actions

Potential Special

Characteristics

Practice Exercise 2

___ System___ Subsystem___ ComponentModel Year / Vehicle(s):Core Team:

PotentialFailure Mode and Effects Analysis

Design Responsibility:Key Date:

FMEA Number:Page 1 of 1Prepared by:FMEA Date ( Orig): (Rev)

Action ResultsPotentialFailureMode

PotentialEffect(s)

of Failure

Sev

Class

PotentialCause(s)/

MechanismsFailure

Occur

CurrentDesign

Controls

Detec

RPN

RecommendedAction(s)

Responsibility &Target

Completion DateActionsTaken

Sev

Occ

Det

RPN

Item

Function

Design FMEA -- Path 1

Potential Failure Modes

5-8

___ System___ Subsystem___ ComponentModel Year / Vehicle(s):Core Team:

PotentialFailure Mode and Effects Analysis

Design Responsibility:Key Date:

FMEA Number:Page 1 of 1Prepared by:FMEA Date ( Orig): (Rev)

Action ResultsPotentialFailureMode

PotentialEffect(s)

of Failure

Sev

Class

PotentialCause(s)/

MechanismsFailure

Occur

CurrentDesign

Controls

Detec

RPN

RecommendedAction(s)

Responsibility &Target

Completion DateActionsTaken

Sev

Occ

Det

RPN

Item

Function

Function 1

Potential Failure Modes:• No function• Partial function• Intermittent function• Unintended function

Function 2

Function 3

Function 4

Function n

Potential Failure Modes

No function

Partial function

Intermittent function

Unintended function

Failure Mode Type Potential Failure Mode

Not operational

Not all of function operating

Occasionally does not function

Unexpected function occurs

3-21

Failure Modes -- Vertical Trimmer

No function No adjustment

Partial function Adjustment in one direction

Intermittent function Adjustment sometimes and not at others

Unintended function Trimmer itself produces light

Failure Mode Type Potential Failure Mode

Failure Mode: Adjust Light Beam Xin Both Directions

___ System___ Subsystem___ ComponentModel Year / Vehicle(s):Core Team:

PotentialFailure Mode and Effects Analysis

Design Responsibility:Key Date:

FMEA Number:Page 1 of 1Prepared by:FMEA Date ( Orig): (Rev)

Action ResultsPotentialFailureMode

PotentialEffect(s)

of Failure

Sev

Class

PotentialCause(s)/

MechanismsFailure

Occur

CurrentDesign

Controls

Detec

RPN

RecommendedAction(s)

Responsibility &Target

Completion DateActionsTaken

Sev

Occ

Det

RPN

Item

Function

Effects of Failure Modes

5-10

Effects of Failure Modes

___ System___ Subsystem___ ComponentModel Year / Vehicle(s):Core Team:

PotentialFailure Mode and Effects Analysis

Design Responsibility:Key Date:

FMEA Number:Page 1 of 1Prepared by:FMEA Date ( Orig): (Rev)

Action ResultsPotentialFailureMode

PotentialEffect(s)

of Failure

Sev

Class

PotentialCause(s)/

MechanismsFailure

Occur

CurrentDesign

Controls

Detec

RPN

RecommendedAction(s)

Responsibility &Target

Completion DateActionsTaken

Sev

Occ

Det

RPN

Item

Function

Function 2

Potential Effects of Failure Modes:• Part / Sub-component• Assembly• System• Vehicle• Government Regulations• Customer (Internal and End User)

Function 1

Failure Mode 1

Failure Mode n

Function n

5-11

Design FMEA -- Effects Table

Failure

Mode

Doesn’t

Retain

Setting

Assbly

Headlamp

Cannot be Adjusted

System

Lt System

Misaligned Lightbeam

Vehicle

(-)

Impaired Night/Fog

Perforsmance

Gov’t

Regs

Road Vehicle

Light Regs ‘89

F/CMVSS Non-

Compliance

Custmr

Driver

Impaired Night/Fog

Vision

Vertical Trimmer

Part / SC

Trimmer

May Be Stripped By Adjustment

Attempt

___ System___ Subsystem___ ComponentModel Year / Vehicle(s):Core Team:

PotentialFailure Mode and Effects Analysis

Design Responsibility:Key Date:

FMEA Number:Page 1 of 1Prepared by:FMEA Date ( Orig): (Rev)

Action ResultsPotentialFailureMode

PotentialEffect(s)

of Failure

Sev

Class

PotentialCause(s)/

MechanismsFailure

Occur

CurrentDesign

Controls

Detec

RPN

RecommendedAction(s)

Responsibility &Target

Completion DateActionsTaken

Sev

Occ

Det

RPN

Item

Function

Design FMEA -- Severity

5-13

Criteria: Severity of Effect RankingEffect

... affects safe vehicle operation and/or government regulation without warning 10

Hazardous With Warning

Hazardous Without Warning

... affects safe vehicle operation and/or government regulation with warning 9

Low… operable at reduced level of performance. Customer experience some dissatisfaction

5

None No Effect1

Suggested Severity Evaluation Criteria

Vertical Trimmer/

Retains Setting

Potential Failure Mode

Does not maintain

adjustment

Potential Effects of Failure

Part: May be stripped during adjustment (7)

Assembly: Headlamp cannot be adjusted (6)

System: Misaligned lightbeam (8)

Vehicle: Impaired night/fog performance (7)

Govt Regs: Non-compliance (10)

Customer: Impaired night/ fog (7)

10

DFMEA Severity Rating Example

SEV

Item

Function

___ System___ Subsystem___ ComponentModel Year / Vehicle(s):Core Team:

PotentialFailure Mode and Effects Analysis

Design Responsibility:Key Date:

FMEA Number:Page 1 of 1Prepared by:FMEA Date ( Orig): (Rev)

Action ResultsPotentialFailureMode

PotentialEffect(s)

of Failure

Sev

Class

PotentialCause(s)/

MechanismsFailure

Occur

CurrentDesign

Controls

Detec

RPN

RecommendedAction(s)

Responsibility &Target

Completion DateActionsTaken

Sev

Occ

Det

RPN

Item

Function

DFMEA -- Recommended Actions

5-32

Select and Manage Actions

Consider This Action: To Accomplish This:To Reduce:

Change the design ... Eliminate failuremode(s) ...

Severity

3-37

YC

S=9 S=10

Design FMEA

Identify Potential Special Characteristics

7-11

Practice Exercise 2

Failure Modes Effects Severity

Recommended Actions Classifications

BreakBreakBreakBreak

FMEAplus

Managing FMEAs

Presentation -- Practice 2

TechnicTechnical al

DebriefDebrief

TechnicTechnical al

DebriefDebrief

Team Team DebriefDebriefTeam Team

DebriefDebrief

Section Summary

Day 1Day 1

DFMEA -- Path DFMEA -- Path 11

Failure Modes

Effects -- Severity

Recommended Actions

Potential Special

Characteristics

Practice Exercise 2

Warm-Down -- Day 1

AgendaAgendaPurposePurpose

TeamTeamOthersOthersSelfSelfPlacePlace

Course Purpose

These three days are designed

to ...

help you function effectively

as an FMEA team member,

but not to leave as an FMEA

team leader or an FMEA expert

Day 1

Failure Mode and Effects Analysis