Failure Mode Effect Analysis

Failure Mode Effect AnalysisIntroduction and ExampleDr. Kylash Makenji

• Introduction and Overview

• What is Failure Mode Effect Analysis (FMEA)?

• Who uses FMEA?

• Pre-requisites

• Working through a FMEA, Example

• RPN’s, What to do next

• Team exercise

Contents

Introduction and Overview

What is FMEA?

Who uses FMEA?

• Automotive

– Jaguar Land rover, Ford, BMW, Honda, VW group

– All of the others……

• Aerospace

– Boeing, Airbus, NASA

• Military

– Armed forces, Air and Sea

• Prior to FMEA you need– A design, process or function

– Bill of materials (BOM)

– A specification, target or objective

– Cross functional team, designer, engineer, manufacturing team………

• Additionally– Standard operating procedure

– Ability to influence or change

– Team skills and competencies, who does what

Pre-requisites

Working through a FMEA

Document and steps overview

Use FMEA anywhere

Buying some milk

Action Results

Item / FunctionPotential Failure

Mode(s)Potential Effect(s)

of Failure

S

e

v

PotentialCause(s)/

Mechanism(s) ofFailure

O

c

c

u

r

r

Current DesignControls - Prevention

Current DesignControls - Detection

D

e

t

R

P

N

RecommendedAction(s)

Responsibility &Target

Completion DateActions Taken

New

Sev

New

Occ

New

Det

New

RP

N

Buy milk forlactose intolerantchild

None available instore

No breakfast forthe little one

3 Shop runs out ofmilk

4 Stock management,EPOS, monitoring levelof sales,

Review of stock levels,visual check of shelvesand warehouse

3 36

3 Shop does notstore that variety

10 Store policy Review of stock levels,visual check of shelvesand warehouse

1 30

I buy the incorrectone

Child hasbreakfast and hasa bad reaction

7 Not in the samelocation in thestore

3 Standard stock andstore layout

Clear labelling of thestorage area, teamtraining

4 84 Not all teammembers canread English,investigate howto improve

Mgr., xx/xx/xx English test andtraining

Incorrect milk incontainer,labelling error


7 Dairy has filledthe incorrectcontainer

1 Dedicated lactose freeproduction line

Batch testing of themilk

2 14

7 Dairy has usedthe wrong labels

2 Dedicated lactose freeproduction line, andpackaging

Batch testing of themilk and packaging,consignmentacceptance check,training of staff

2 28

Spill milk before Iget home


3 Screw on cap notsecure

2 Screw cap fitting isautomated, torquesetting on equipment


6 36 Investigatecalibrated screwon and off device

Milk on floor,danger ofslippage

6 Container too thinto hold milk, splitin side wall

3 Automated andestablished process, inline wall sectionchecks


2 36

Log, dates, team members, design numbers and versionsList a design, function or process items

Action Results



of Failure

S

e

v

PotentialCause(s)/


O

c

c

u

r

r



D

e

t

R

P

N




New

Sev

New

Occ

New

Det

New

RP

N







3 36



1 30













2 14




2 28











2 36

Record any and all potentialfailure modes

Action Results



of Failure

S

e

v

PotentialCause(s)/


O

c

c

u

r

r



D

e

t

R

P

N




New

Sev

New

Occ

New

Det

New

RP

N







3 36



1 30













2 14




2 28











2 36

List the potential effects of thefailure

• How severe is the failure mode to customers?

– 10 = very severe, may kill

– 1 = no effectEffect SEVERITY of Effect Ranking

Hazardous without warning Very high severity ranking when a potential failure mode affects safe system operation without warning 10

Hazardous with warning Very high severity ranking when a potential failure mode affects safe system operation with warning 9

Very High System inoperable with destructive failure without compromising safety 8

High System inoperable with equipment damage 7

Moderate System inoperable with minor damage 6

Low System inoperable without damage 5

Very Low System operable with significant degradation of performance 4

Minor System operable with some degradation of performance 3

Very Minor System operable with minimal interference 2

None No effect 1

Severity

Action Results



of Failure

S

e

v

PotentialCause(s)/


O

c

c

u

r

r



D

e

t

R

P

N




New

Sev

New

Occ

New

Det

New

RP

N







3 36



1 30













2 14




2 28











2 36

Action Results



of Failure

S

e

v

PotentialCause(s)/


O

c

c

u

r

r



D

e

t

R

P

N




New

Sev

New

Occ

New

Det

New

RP

N







3 36



1 30













2 14




2 28











2 36

List the causes of failure

• How likely will the fault occur ?

– Use data, explicit and tacit knowledge

– If available, look at warranty and customer data

OCCURRENCE of Failure Failure Prob Ranking

Very High: Failure is almost inevitable >1 in 2 10

1 in 3 9

High: Repeated failures 1 in 8 8

1 in 20 7

Moderate: Occasional failures 1 in 80 6

1 in 400 5

1 in 2,000 4

Low: Relatively few failures 1 in 15,000 3

1 in 150,000 2

Remote: Failure is unlikely <1 in 1,500,000 1

Occurrence

Action Results



of Failure

S

e

v

PotentialCause(s)/


O

c

c

u

r

r



D

e

t

R

P

N




New

Sev

New

Occ

New

Det

New

RP

N







3 36



1 30













2 14




2 28











2 36

If available use warrantee andcustomer data

Action Results



of Failure

S

e

v

PotentialCause(s)/


O

c

c

u

r

r



D

e

t

R

P

N




New

Sev

New

Occ

New

Det

New

RP

N







3 36



1 30













2 14




2 28











2 36

What is in place to prevent thefailure occurring

Action Results



of Failure

S

e

v

PotentialCause(s)/


O

c

c

u

r

r



D

e

t

R

P

N




New

Sev

New

Occ

New

Det

New

RP

N







3 36



1 30













2 14




2 28











2 36

What is in place to detect thefailure occurring

• How likely are you to detect the failure throughcontrols, before your customer does?

Detection Likelihood of DETECTION by Design Control Ranking

Absolute Uncertainty Design control cannot detect potential cause/mechanism and subsequent failure mode 10

Very Remote Very remote chance the design control will detect potential cause/mechanism and subsequent failure mode 9

Remote Remote chance the design control will detect potential cause/mechanism and subsequent failure mode 8

Very Low Very low chance the design control will detect potential cause/mechanism and subsequent failure mode 7

Low Low chance the design control will detect potential cause/mechanism and subsequent failure mode 6

Moderate Moderate chance the design control will detect potential cause/mechanism and subsequent failure mode 5

Moderately High Moderately High chance the design control will detect potential cause/mechanism and subsequent failure mode 4

High High chance the design control will detect potential cause/mechanism and subsequent failure mode 3

Very High Very high chance the design control will detect potential cause/mechanism and subsequent failure mode 2

Almost Certain Design control will detect potential cause/mechanism and subsequent failure mode 1

Detection

Action Results



of Failure

S

e

v

PotentialCause(s)/


O

c

c

u

r

r



D

e

t

R

P

N




New

Sev

New

Occ

New

Det

New

RP

N







3 36



1 30













2 14




2 28











2 36

Action Results



of Failure

S

e

v

PotentialCause(s)/


O

c

c

u

r

r



D

e

t

R

P

N




New

Sev

New

Occ

New

Det

New

RP

N







3 36



1 30













2 14




2 28











2 36

Risk Priority Number, (RPN)Severity x occurrence x detection = RPN

• Sort the FMEA in descending order– Create actions to reduce RPN value

– Strive to continually improve

– If you have further data, rework back into FMEA

– Some actions may not reduce the RPN significantly

• Beyond economical feasibility

• Simulate and test to measure the impact to the RPN score

RPN’s, What to do Next?

Action Results



of Failure

S

e

v

PotentialCause(s)/


O

c

c

u

r

r



D

e

t

R

P

N




New

Sev

New

Occ

New

Det

New

RP

N







3 36



1 30













2 14




2 28











2 36

Action Results



of Failure

S

e

v

PotentialCause(s)/


O

c

c

u

r

r



D

e

t

R

P

N




New

Sev

New

Occ

New

Det

New

RP

N







3 36



1 30













2 14




2 28











2 36

Action Results



of Failure

S

e

v

PotentialCause(s)/


O

c

c

u

r

r



D

e

t

R

P

N




New

Sev

New

Occ

New

Det

New

RP

N







3 36



1 30













2 14




2 28







KM – 01/09/15 £120K ofinvestmentrequired, unableto justify givenpayback period





2 36

Work with thehighest RPN, anddownwards, strivingto continuallyimproveActions, targets etc

Action Results



of Failure

S

e

v

PotentialCause(s)/


O

c

c

u

r

r



D

e

t

R

P

N




New

Sev

New

Occ

New

Det

New

RP

N







3 36



1 30













2 14




2 28












2 36

Recalculatenew RPNwith actioncompleted orto predict

Action Results



of Failure

S

e

v

PotentialCause(s)/


O

c

c

u

r

r



D

e

t

R

P

N




New

Sev

New

Occ

New

Det

New

RP

N







3 36



1 30













2 14




2 28












2 36

Some actionsmay not be

feasible to putinto place,

technical oreconomic

considerations

Action Results



of Failure

S

e

v

PotentialCause(s)/


O

c

c

u

r

r



D

e

t

R

P

N




New

Sev

New

Occ

New

Det

New

RP

N







3 36



1 30













2 14




2 28











2 36Next time if you are doing a similar product orprocess use an existing FMEA, develop andimprove

Team Activity

Team 1 – Installing the sliding switchTeam 2 – Connecting the sliding switch

Team 3 – User behaviour, using the sliding switch

Volume Slide

• Specification and details:-– Moving slide left to right will increase volume

– Calibrated slide

• 50% movement = 50% sound increase

– Steel body construction

– Plastic slide knob

– Held in place by 2 screws, onto the PCB

– 2 black wires to connect it to the PCB

Slide Volume

PLAN VIEW

UNDERSIDE / ELECTRICAL CONNECTION

ELECTRICALCONNECTIONSx2

FIXING LUGSx2

SLIDER

• Function is part of the design which is intentional as part of theoverall specification

• How is the specification being delivered

– i.e. a volume slide

– What can go wrong with it?

• Function, assembly

Function and potential failure mode

• What can go wrong with function and design of the volumeslide?

• Brainstorm

– Ishikawa diagram

Brainstorm

Ishikawa diagram (fishbone)

EQUIPMENT PROCESS PEOPLE

MATERIALS ENVIRONMENT MANAGEMENT

PR

OB

LEM

POOR SOLDERING-INCORRECT EQUIPMENT-TOO HOT / COLD- NOT CALIBRATED

Item / Function Potential Failure Mode(s)Potential Effect(s)

of Failure

S

e

v

Potential Cause(s)/Mechanism(s) of Failure

O

c

c

u

r

r

Current Design Controls - Prevention Current Design Controls - Detection

D

e

t

R

P

N

Scoring overview

SEVERITY OCCURRENCE FAILURE PROBABILITY DETECTION RANKING

Hazardous without warning Very High: Failure is inevitable >1 in 2 Absolute Uncertainty 10

Hazardous with warning 1 in 3 Very Remote 9

Very High High: Repeated failures 1 in 8 Remote 8

High 1 in 20 Very Low 7

Moderate Moderate: Occasional failures 1 in 80 Low 6

Low 1 in 400 Moderate 5

Very Low 1 in 2,000 Moderately High 4

Minor Low: Relatively few failures 1 in 15,000 High 3

Very Minor 1 in 150,000 Very High 2

None Remote: Failure is unlikely <1 in 1,500,000 Almost Certain 1

Any questions?

Technology

Failure Mode Effect Analysis