FMEA

FMEA – How to Plan and Organize

N b 14 2006November 14, 2006

Minnesota ASQ

Jim McLinn CRE, Fellow ASQ

Slide 1

FMEA

N k d FMEANaked FMEAs

What is it?

Wh d FMEA?Why do an FMEA?

What is it good for?What is it good for?

How to do an FMEA

When to do an FMEA

Slide 2

FMEA

HistoryHistory1960s – NASA began a version1974 US Military and Mil Std 16291978 – FDA issued Hazard Analysis1988 - Ford issued a new document for suppliers1990 – Chemical and Gas industry1994 – ISO recommended Design and P FMEAProcess FMEAs1996 – FDA issued recommendation on FMEA

Slide 3

FMEAs

FMEA

Source of DocumentsSource of Documents

Mil Std 1629IEC 812ARP 5580RADC TR83-72AIAG & SAE J1739VDI – Z138 (German)( )British StandardsOther forms exist

Slide 4

Other forms exist

FMEA

Th FMEA A dThe FMEA Agenda

FMEAs can be done for a product design or a wide variety of business processesor a wide variety of business processes.

The intent is to improve the design or process by finding potential problems and

avoiding them.

Slide 5

FMEA Key FMEA Terms

Failure ModeThe manner in which a part or assembly could potentially fail to meet it’s requirements or fail to function. It is what you may reject the part for.

EffectsThe potential non-conformance stated in the terms of the next assembly or at the system (top level) performance (usually from the customer’s perspective).y ( p ) p ( y p p )

CausesThe potential reason(s) behind a failure mode, usually stated as an indication of a specific design or process weakness. This starts the chain of events leading to p g p gthe Effect.

AnalysisBy using an FMEA model you will anticipate failure modes determine andBy using an FMEA model, you will anticipate failure modes,determine and assess risk to the customer, product or process, and then act to neutralize the risk or reduce it to acceptable levels

RPN

Slide 6

RPNRisk Priority Number which helps prioritize the findings of the FMEA

FMEA Benefits of Using FMEAs

Improves time to get reliable products to market

Can reduce or prevent recalls (Sony recalled 9 6 million batteries in 2006)recalled 9.6 million batteries in 2006)

Identifies downstream maintenanceIdentifies downstream maintenance considerations early

May aid in complaint investigation and meaningful corrective actions of a process

Slide 7Many others exist

FMEA

Team Formation ChallengesTeam Formation Challenges1. Team Formation

All people must participate with no dominant starsShould be small: 5 - 8 People are bestMulti-Disciplined should be presentMulti Disciplined should be presentProduct/Process Knowledge is keyResponsibility Level - Must have the authority to

get things doneg gCustomer Oriented – Driven to prevent problems

for customersSee Sept 2006 Quality Progress – but watch for errors in article

Slide 8

FMEA Additional Considerations2 Organization of a Team2. Organization of a Team

Team Sponsor ( need not be present)Team Leader (must be present and move team along)Team Leader (must be present and move team along)Support GroupsDesign Engineering • Electrical, Software or Mechanical people, p p• Manufacturing or Operations• Test Engineering• Reliability Engineeringy g g• Field Service or repair

ScribeC h f iliCoach or facilitator

Slide 9

FMEA Design vs. Process FMEAs

Design FMEAEngineer designs to fulfill customer requirementsg g q

Failure Mode = Failure to functionCause = Design weaknessDetection = Really verification and Validation (catchDetection = Really verification and Validation (catch

design weakness before release tomanufacturing)

Process FMEAEngineering design process to meet specificationg g g p p

Failure Mode = Reject (Out of specification)Cause = Process weaknessDetection = Controls in place on process to prevent

Slide 10

Detection = Controls in place on process to prevent rejects from reaching the customer.

FMEA When to do Design & Process FMEAs

Project Phases…

Phase 1: Phase 2: Phase 3: Phase 5:Phase 4:Concept

DevelopmentProductPlanning

Design &Development

Release& Ramp

Test &Validation

Initial Design Complete

Design FMEAg

Process FMEA

Apply learning from previous projects

Slide 11

FMEA Some Related Tools

Function A Function B Function C

Functional Block DiagramsFunctional Block DiagramsFault Tree AnalysisFlow DiagramsFlow DiagramsProcess MappingMany other tools existMany other tools exist

Slide 12

FMEA Functional Block Diagrams

Is a tool to describe the operation of i f i ta piece of equipment or process.

Allows all team members to develop a shared understanding of the operation or g pprocess to be improved.Develops a concise starting point andDevelops a concise starting point and ending point for analysis of the system.

Slide 13

FMEA FBD Example: Smoke Detector

Smoke Chamber circuit - ionizes smoke which cases increase in voltage corresponding to signal to be sent to control box

Indicator light - shines when battery test button is depressed or when alarm is activated

Vents – to smoke chamber circuit

+

Battery - supplies voltage to entire system

Control Box - controls

Wire - for sending signal to control box

Test Button –Activates horn

Siren - receives voltage and in turn produces sound.

HornControl wire - sends voltage wire to siren

voltage to siren system units

Activates horn

How the Smoke Detector works: Smoke enters the vent and goes into the smoke chamber 2) The chamber detects the presence of certain traces of smoke 3) If enough smoke is present chamber sends signal to control box 4) control box then draws most of voltage in entire system to siren 5)Voltage from

Hornvoltage wire to siren

Slide 14

signal to control box 4) control box then draws most of voltage in entire system to siren 5)Voltage from battery in turn activates obnoxious siren sound

FMEA FBD Example: Smoke Detector

Inputs Process Outputs

Smoke enters chamber Light is activated

Presence of smoke Smoke enters assembly Successful capture

Smoke passes detector

Ion chamber generates

Voltage goes to control box

Ion chamber generates voltage

Control box sends voltage to Noise Maker

Loud Noise

Alarm Sounds

Slide 15

Loud Noise

FMEA Fault Tree

What ?A logical connection diagram that shows a series of related events which lead to potential root cause(s) of a failure.

When ?As part of a design reviewAs part of a design reviewWhen developing a new processTo analyze a failurey

Why? To minimize high risk or weak links in a design To reduce/eliminate process weaknessesTo understand root cause(s) of a failure in a multiple connection or interaction environment.

Slide 16

co ect o o te act o e v o e t.

FMEA Smoke Detector Fault TreeSmoke Detector Fails to Detect

SmokePartial Block Diagram

Smoke doesnot enterchamber

Smoke doesnot enter the

assembly

Smoke notdetected inchamber

Vent isblocked Dust Detector

broken

Slide 17

Paint Dust Insects Incorrectinstallation

Mechanicalshock

Electricaloverstress

Temperatureextreme

Dead or lowbattery

FMEA FMEAs - Failure Modes & Effects Analysis

What ? - Answered

When ? – Answered

Wh A dWhy - Answered

Time for a short example !!Time for a short example !!

Slide 18

FMEA FMEAs - Failure Modes & Effects Analysis

Sample DFMEA FormSample DFMEA Form

Slide 19

FMEA FMEA Fault Tree to Failure Modes & Cause(s)

Smoke doesnot enter the

assembly

Vent isblocked

MultipleLevel OptionTies to FTALevels blockedLevels

Paint Dust Insects Incorrectinstallation

Each of the lowest level entries in the Fault Tree are potential Causes for the Failure Modes

Slide 20

pThere should be at least one Cause for each Failure Mode branch

FMEA FMEA Effects and Fault Detection

Next we complete the Effects and Fault Detection columns together.

Slide 21

FMEA FMEA SeverityNext complete the Severity columnNext complete the Severity column.Severity may ranked from 1 to 10 or as a 1 to

i ( b )5 for simple systems (Big number most severe).OR

1- Failure Mode is of such a minor nature that special equipment or1- Failure Mode is of such a minor nature that special equipment or knowledge is required to identify. This is NO IMPACT to System.

2 - Failure Mode will result in a slight system impact and / or a slight deterioration of system performancedeterioration of system performance.

3 - Failure Mode will result in noticeable system deterioration and may be described as a “limp along”.

4 Fail re Mode ill res lt in a non f nction of a critical s stem item4 - Failure Mode will result in a non-function of a critical system item. 5 - Failure Mode will result in a safety problem or non-compliance with

government regulation.

Slide 22

FMEA FMEA Detection or VerificationDetectability can be ranked from 1 to 10 or 1Detectability can be ranked from 1 to 10 or 1 to 5(Big number is least likely to be identified in Product Development)Product Development).OR

1 - Very high probability that the Failure Mode will be identified. Verification or Validation (V&V) or other activity will almost certainly identify the existence of the (potential) defect.

2 - High probability that the Failure Mode will be identified. V&V or other activities have a good chance of identifying the existence of the defect.

3 - Moderate probability that the Failure Mode will be identified. V&V or other activities are moderately likely to identify the existence of the defect.

4 - Low probability that the Failure Mode will be identified. V&V or other activities are not likely to identify the defect.

5 - Very low probability that the Failure Mode will be identified. V&V or

Slide 23

y p yother activities will not or cannot identify the existence of a defect.

FMEA FMEA Occurrence

Occurrence may be ranked from 1 to 10 or 1 to 5 – as always big numbers are badRanking:1 more then 10 Years between fails2 5 to 10 years OR2 5 to 10 years OR3 2 to 5 years 1 - Less then 0.1%4 1 to 2 years 2 - 0.1% to 1%

The Scale Factor may be changed as long as it is applied consistently e g one5 ½ to 1year 3 – 1% to 10%

6 Quarterly 4 – 10% to 50%7 Monthly 5 – More then 50%

applied consistently, e.g., one minute might be a 10 and twenty four hours might be a 1y

8 Weekly9 Daily10 Every few hours

a 1.

Rule of Thumb: A 1 should be at least the expected life

Slide 24

10 Every few hours pof the product.

FMEA FMEA Risk Priority Number

Calculate the Risk Priority and find top 20%Calculate the Risk Priority and find top 20%

RPN is the product of S*D*O.

Top 20% are big impact items to improve

Also include all safety items to prevent or mitigate

Look at any remaining top Severity items

Slide 25

FMEA FMEA Recommended Actions

Fill out the Recommended Actions based on:Fill out the Recommended Actions based on:Safety Issue = YesRPN ranking (start with the top 20%)RPN ranking (start with the top 20%)When should we do more than 20%?

Easy fixes that require minimal resourcesOthers that the team feels are important

Slide 26

FMEA FMEA Who & When

Slide 27

FMEA FMEA Audit

Key to closing out actions and making something happen

Slide 28

FMEA FMEA Suggestions

Take advantage of existing dataUse field experience and talk to service or repair peopleFacilitate proper brainstorming – Learn how!Avoid jumping to solutions – A Common

i i iEngineering MistakeDon’t get bogged down in argumentsA Recommended Action might be another FMEA or a study

Slide 29

FMEAKeep Metrics of the FMEA – For p

Example look at Statistics:

• Total number of entriesTotal number of entries

• Total number of Safety items

• Make a RPN Histogram

• Identify Entries requiring workIdentify Entries requiring work

• Do man-load time estimates of meetingsg

•Create a “Parking lot” if necessary

Slide 30

FMEA

Congratulations, you have covered th FMEA ti the FMEA portion; now it is time to address theaddress theMANAGEMENT of the FMEA

Slide 31

FMEA

Ways to Improve FMEAsWays to Improve FMEAs

•Make sure there is management buy-in

•Spend lots of time with group in FMEAp g p

•Plan, Plan, Plan

•Come with forms filled outCome with forms filled out

•Identify purpose, limits, goals and customers.

D fi ll t f t•Define all terms up front.

•Set aside enough time.

Slide 32

•Do the follow up

FMEA

Train the TeamTrain the Team

Be sure to include training time for teamHave drawings and aides at hand.R t ti f 2 t 3 h dRun team meetings for 2 to 3 hours and then stop.Come prepared to all meetingsCome prepared to all meetingsLet the team work the issues

Slide 33

FMEA

Watch Your WordsWatch Your Words

Use a complete sentence to express a complete idea.Need a complete thought, so no stand alone words in a sectionsectionAvoid vague words such as:

Bad, Poor & WronggToo, Low & NoBroken, Dead & FailedInsufficient unacceptable or similar wordsInsufficient, unacceptable or similar words

Slide 34

FMEADon’t get Confused:gWrite out whole progression if necessary

Root CauseMechanism

D f tDefectGrowth

FailureFailureFailure Mode

Next level impactpTop level Effects

Slide 35

FMEA

Other types of FMEAs

Process FMEAs are commonMaintenance or service FMEAs are doneF i l it h H dFocus on single item such as HazardsFMEA covering something newFunctional level FMEAsFunctional level FMEAs

Try each one, but remember they might have different y , y gformats or requirements.

Slide 36

FMEA

Get the relationships CorrectGet the relationships Correct

Severity is the numerical equivalent of EffectsOccurrence speaks to likelihood of CauseV ifi ti t lk b t d f V&V t tVerification talks about adequacy of V&V tests.For a process FMEA, Detection talks about adequacy of Current Controls.of Current Controls.

NEVER, NEVER, NEVER depend upon the customer to find or detect problems.

Slide 37

FMEA

Team Dynamics

Use the 30, 60 , 5 RuleDon’t allow arguments or hidden agendas

Encourage discussion for a short time and then either:then either:

Come to a conclusionCreate an action to get informationU th ki l tUse the parking lot

Slide 38

FMEA

FMEA MythsFMEA Myths

It takes a lot of timeJust a pile of paperwork in the endC ti ti t t hCorrective actions cost too muchDifficult to implement FMEAs because of roadblocksroadblocksDesign Engineers job, not othersNo body really cares anywayNot cost effectiveStill can’t prevent safety problems

Slide 39

FMEA

I C l iIn Conclusion

Come PreparedKeep it simpleKeep it focusedKeep it shortKeep it movingFollow up on action itemspPractice your team leader skillsCollect Lessons Learned

Slide 40

Collect Lessons Learned