unit-2 - fmea

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FMEA

Failure Mode Effects Analysis

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y

Quality and Reliability Quality is a relative term often based on customer

perception or the degree to which a product meetscustomer expectations

Manufacturers have long recognized that products

can meet specifications and still fail to satisfy

customer expectations due to

!Errors in design

!Flaws induced by the manufacturing process

!Environment

!"roduct misuse

!#ot understanding customer wants$needs

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Quality% Reliability and Failure

"revention &raditionally 'uality activities have focused

on detecting manufacturing and materialdefects that cause failures early in the life

cycle

&oday% activities focus on failures that

occur beyond the infant mortality stage

Emphasis on Failure Prevention

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Failure Mode ( Effects Analysis

)FMEA* FMEA is a systematic method of identifying and

preventing system% product and process problemsbefore they occur

FMEA is focused on preventing problems%enhancing safety% and increasing customersatisfaction

+deally% FMEA,s are conducted in the productdesign or process development stages% althoughconducting an FMEA on existing products or

processes may also yield benefits

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FMEA$FME-A .istory &he history of FMEA$FME-A goes bac/ to

the early 0123s and 0143s5! 6575 #avy 8ureau of Aeronautics% followed by

the 8ureau of #aval 9eapons

!#ational Aeronautics and 7paceAdministration )#A7A*

:epartment of :efense developed andrevised the M+;

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FMEA$FME-A .istory (continued)

Ford Motor -ompany published instructionmanuals in the 01?3s and the automotive

industry collectively developed standards in

the 0113s5 Engineers in a variety of industries have

adopted and adapted the tool over the years5

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"ublished @uidelines 0>B1from the SAE for the automotive

industry.

A+A@ FMEA

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Cther @uidelines

Cther industry and company

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FMEA is a &ool

FMEA is a tool that allows you to

!"revent 7ystem% "roduct and "rocess problemsbefore they occur

!reduce costs by identifying system% product and

process improvements early in the developmentcycle

!-reate more robust processes

!"rioritize actions that decrease ris/ of failure

!Evaluate the system%design and processes from a

new vantage point

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A 7ystematic "rocess

FMEA provides a systematic process to

! +dentify and evaluate

potential failure modes

potential causes of the failure mode

! +dentify and 'uantify the impact of potential failures

! +dentify and prioritize actions to reduce or eliminate

the potential failure

! +mplement action plan based on assigned

responsibilities and completion dates

! :ocument the associated activities

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"urpose$8enefit

cost effective tool for maximizing anddocumenting the collective /nowledge%experience% and insights of the engineeringand manufacturing community

format for communication across thedisciplines

provides logical% se'uential steps forspecifying product and process areas ofconcern

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8enefits of FMEA

-ontributes to improved designs for products andprocesses5

! .igher reliability

! 8etter 'uality

! +ncreased safety! Enhanced customer satisfaction

-ontributes to cost savings5

! :ecreases development time and re

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8enefits

-ost benefits associated with FMEA are usuallyexpected to come from the ability to identify failuremodes earlier in the process% when they are lessexpensive to address5! rule of ten

+f the issue costs G033 when it is discovered inthe field% thenD

+t may cost G03 if discovered during the finaltestD

8ut it may cost G0 if discovered during anincoming inspection5

Even better it may cost G3503 if discoveredduring the design or process engineering phase5

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FMEA as .istorical Record

-ommunicate the logic of the

engineers and related design and

process considerations

Are indispensable resources for new

engineers and future design and

process decisions5

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7ystem :esign "rocess

-omponents

7ubsystems

Main 7ystems

-omponents

7ubsystems

Main 7ystems

ManpowerMachine

Method

Material

Measurement

Environment

Machines

&ools%

9or/ 7tations%

"roduction ;ines%

Cperator &raining%

"rocesses%

@auges

Focus

Minimize failureeffects on the

7ystem

CbHectives$@oal

Maximize 7ystemQuality% reliability%

-ost and

maintenance

Focus

Minimize failureeffects on the

:esign

CbHectives$@oal

Maximize :esignQuality% reliability%

-ost and

maintenance

Focus

Minimize failure

effects on the

"rocesses

CbHectives$@oal

Maximize

&otal "rocess

Quality% reliability%

-ost and

maintenance

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9hy do FMEA,sI

Examine the system for failures5

Ensure the specs are clear and assure the

product wor/s correctly

+7C re'uirement

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9hat tools are available to meet

our obHectiveI 8enchmar/ing

customer warranty reports

design chec/list or guidelines

field complaints internal failure analysis

internal test standards

lessons learned

returned material reports

Expert /nowledge

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9hat are possible outcomesI

Actual$potential failure modes

customer and legal design re'uirements

duty cycle re'uirements

product functions

/ey product characteristics

"roduct Jerification and Jalidation

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.ow to FmeaD&he "re

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.ow to FMEA55 )cont5*

&he purpose of this meeting is to

!:etermine scope

!@ather bac/ground reference material

!-reate update bloc/ diagrams

!+dentify team members

!"repare an agenda% schedule% milestones

!+dentify item functions% failure modes andtheir effects

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Assumptions of :FMEA

All systems$components are manufactured

and assembled as specified by design

Failure could% but will not necessarily%

occur

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:esign FMEA Format

DetectPrevent

R

P

N

D

E

T

O

C

C

S

E

V

ActionTaken

Action ResultsResponse &

Target

Complete

Date

Recommended

Actions

R

P

N

D

e

t

ec

CurrentDesign

Controls

O

c

c

ur

PotentialCause(s!

"ec#anism(s

O$ %ailure

C

l

a

ss

S

e

v

Potential

E$$ect(s o$

%ailure

Potential

%ailure

"ode

tem

DetectPrevent

R

P

N

D

E

T

O

C

C

S

E

V

ActionTaken


Target

Complete

Date

Recommended

Actions

R

P

N

D

e

t

ec

Current

Controls

O

c

c

ur

PotentialCause(s!

"ec#anism(s

O$ %ailure

C

l

a

ss

S

e

v

Potential

E$$ect(s o$

%ailure

Potential

%ailure

"ode

%unction

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@eneral

Every FMEA should have an assumptions document

attached )electronically if possible* or the first line of theFMEA should detail the assumptions and ratings used for the

FMEA5

"roduct$part names and numbers must be detailed in the

FMEA headerAll team members must be listed in the FMEA header

Revision date% as appropriate% must be documented in the

FMEA header

DetectPrevent

R

P

N

D

E

T

O

C

C

S

E

V

ActionTaken


Target

Complete

Date

Recommended

Actions

R

P

N

D

e

t

ec

CurrentDesign

Controls

O

c

c

ur

PotentialCause(s!

"ec#anism(s

O$ %ailure

C

l

a

ss

S

e

v

Potential

E$$ect(s o$

%ailure

Potential

%ailure

"ode

tem

DetectPrevent

R

P

N

D

E

T

O

C

C

S

E

V

ActionTaken


Complete

Date

Recommended

Actions

R

P

N

D

e

t

ec

Current

Controls

O

c

c

ur

PotentialCause(s!

"ec#anism(s

O$ %ailure

C

l

a

ss

S

e

v

Potential

E$$ect(s o$

%ailure

%unction

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Function

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Function

EKAM";E

.JA- system must defog windows and heat or cool cabin to >3

degrees in all operating conditions )

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"otential Failure mode

:efinition the manner in which a system%subsystem% or component could potentially fail tomeet design intent

As/ yourself< .ow could this design fail to meeteach customer re'uirementI

Remember to consider! absolute failure

!partial failure! intermittent failure

! over function

! degraded function

! unintended function

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Failure Mode

EKAM";E7

.JA- system does not heat vehicle or defog windows

.JA- system ta/es more than 2 minutes to heat vehicle

.JA- system does not heat cabin to >3 degrees in belowzero temperatures

.JA- system cools cabin to 23 degrees

.JA- system activates rear window defogger

DetectPrevent

R

P

N

D

E

T

O

C

C

S

E

V

ActionTaken


Target

Complete

Date

Recommended

Actions

R

P

N

D

e

t

ec

CurrentDesign

Controls

O

c

c

ur

PotentialCause(s!

"ec#anism(s

O$ %ailure

C

l

a

ss

S

e

v

Potential

E$$ect(s o$

%ailure

Potential

%ailure

"ode

tem

DetectPrevent

R

P

N

D

E

T

O

C

C

S

E

V

ActionTaken


Complete

Date

Recommended

Actions

R

P

N

D

e

t

ec

Current

Controls

O

c

c

ur

PotentialCause(s!

"ec#anism(s

O$ %ailure

C

l

a

ss

S

e

v

Potential

E$$ect(s o$

%ailure

%unction

id i l f il d

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-onsider "otential failure modes

under Cperating -onditions

! hot and cold

! wet and dry

! dusty and dirty 6sage

! Above average life cycle

! .arsh environment

!below average life cycle

- id i l f il d

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-onsider "otential failure modes

under +ncorrect service operations

! -an the wrong part be substituted inadvertentlyI

! -an the part be serviced wrongI E5g5 upside down%

bac/wards% end to end

! -an the part be omittedI

! +s the part difficult to assembleI

:escribe or record in physical or technical terms%

not as symptoms noticeable by the customer5

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"otential Effect)s* of Failure

:efinition effects of the failure mode on the function as

perceived by the customer

As/ yourself< 9hat would be the result of this failureI

or +f the failure occurs then what are the conse'uences

:escribe the effects in terms of what the customer might

experience or notice

7tate clearly if the function could impact safety or

noncompliance to regulations +dentify all potential customers5 &he customer may be an

internal customer% a distributor as well as an end user

:escribe in terms of product performance

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Effect)s* of Failure

EKAM";E

-annot see out of front window

Air conditioner ma/es cab too cold

:oes not get warm enough&a/es too long to heat up

DetectPrevent

R

P

N

D

E

T

O

C

C

S

E

V

ActionTaken


Target

Complete

Date

Recommended

Actions

R

P

N

D

e

t

ec

CurrentDesign

Controls

O

c

c

ur

PotentialCause(s!

"ec#anism(s

O$ %ailure

C

l

a

ss

S

e

v

Potential

E$$ect(s o$

%ailure

Potential

%ailure

"ode

tem

DetectPrevent

R

P

N

D

E

T

O

C

C

S

E

V

ActionTaken


Complete

Date

Recommended

Actions

R

P

N

D

e

t

ec

Current

Controls

O

c

c

ur

PotentialCause(s!

"ec#anism(s

O$ %ailure

C

l

a

ss

S

e

v

Potential

E$$ect(s o$

%ailure

%unction

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Examples of "otential Effects

#oise

loss of fluid

seizure of adHacent

surfaces loss of function

no$low output

loss of system

+ntermittent operations

rough surface

unpleasant odor

poor appearance

potential safety hazard

-ustomer dissatisfied

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7everity

:efinition assessment of the seriousness of

the effect)s* of the potential failure mode on

the next component% subsystem% or

customer if it occurs 7everity applies to effects

For failure modes with multiple effects% rate

each effect and select the highest rating asseverity for failure mode

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7everity

EKAM";E

-annot see out of front window ! severity 1

Air conditioner ma/es cab too cold ! severity 2

:oes not get warm enough ! severity 2&a/es too long to heat up ! severity L

DetectPrevent

R

P

N

D

E

T

O

C

C

S

E

V

ActionTaken


Target

Complete

Date

Recommended

Actions

R

P

N

De

t

ec

CurrentDesign

Controls

Oc

c

ur

PotentialCause(s!

"ec#anism(s

O$ %ailure

Cl

a

ss

S

e

v

Potential

E$$ect(s o$

%ailure

Potential

%ailure

"ode

tem

DetectPrevent

R

P

N

D

E

T

O

C

C

S

E

V

ActionTaken


Complete

Date

Recommended

Actions

R

P

N

De

t

ec

Current

Controls

Oc

c

ur

PotentialCause(s!

"ec#anism(s

O$ %ailure

Cl

a

ss

S

e

v

Potential

E$$ect(s o$

%ailure

%unction

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-lassification

-lassification should be used to define potential critical and significantcharacteristics

-ritical characteristics )1 or 03 in severity with = or more in occurrence

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"otential -ause)s*$Mechanism)s* of

failure

:efinition an indication of a design

wea/ness% the conse'uence of which is the

failure mode

Every conceivable failure cause ormechanism should be listed

Each cause or mechanism should be listed

as concisely and completely as possible soefforts can be aimed at pertinent causes

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-ause)s* of Failure

EKAM";E+ncorrect location of vents

+ncorrect routing of vent hoses )too close to heat

source*+nade'uate coolant capacity for application

DetectPrevent

R

P

N

D

E

T

O

C

C

S

E

V

ActionTaken


Target

Complete

Date

Recommended

Actions

R

P

N

De

t

ec

CurrentDesign

Controls

Oc

c

ur

PotentialCause(s!

"ec#anism(s

O$ %ailure

Cl

a

ss

S

e

v

Potential

E$$ect(s o$

%ailure

Potential

%ailure

"ode

tem

DetectPrevent

R

P

N

D

E

T

O

C

C

S

E

V

ActionTaken


Complete

Date

Recommended

Actions

R

P

N

De

t

ec

Current

Controls

Oc

c

ur

PotentialCause(s!

"ec#anism(s

O$ %ailure

Cl

a

ss

Potential

E$$ect(s o$

%ailure

%unction

" t ti l - M h i

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"otential -ause Mechanism &olerance build up

insufficient material insufficient lubrication capacity

Jibration

Foreign Material

+nterference

+ncorrect Material thic/ness specified

exposed location

temperature expansion

inade'uate diameter

+nade'uate maintenance instruction Cver

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Cccurrence

:efinition li/elihood that a specific

cause$mechanism will occur

8e consistent when assigning occurrence

Removing or controlling the

cause$mechanism though a design change is

only way to reduce the occurrence rating

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Cccurrence

EKAM";E

+ncorrect location of vents ! occurrence B

+ncorrect routing of vent hoses )too close to

heat source* ! occurrence 4+nade'uate coolant capacity for application !

occurrence =

DetectPrevent

R

P

N

D

E

T

O

C

C

S

E

V

ActionTaken


Target

Complete

Date

Recommended

Actions

R

P

N

De

t

ec

CurrentDesign

Controls

Oc

c

ur

PotentialCause(s!

"ec#anism(s

O$ %ailure

Cl

a

ss

S

e

v

Potential

E$$ect(s o$

%ailure

Potential

%ailure

"ode

tem

DetectPrevent

R

P

N

D

E

T

O

C

C

S

E

V

ActionTaken


Complete

Date

Recommended

Actions

R

P

N

De

t

ec

CurrentOc

c

ur

PotentialCause(s!

"ec#anism(s

O$ %ailure

Cl

a

ss

S

e

v

Potential

E$$ect(s o$

%ailure

%unction

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-urrent :esign -ontrols :efinition activities which will assure the design ade'uacy

for the failure cause$mechanism under consideration -onfidence -urrent :esign -ontrols will detect cause and

subse'uent failure mode prior to production% and$or willprevent the cause from occurring

! +f there are more than one control% rate each and select the lowest forthe detection rating

-ontrol must be allocated in the plan to be listed% otherwiseit,s a recommended action

B types of -ontrols

! 05 "revention from occurring or reduction of rate! =5 :etect cause mechanism and lead to corrective actions

! B5 :etect the failure mode% leading to corrective actions

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-urrent :esign -ontrols

EKAM";E

Engineering specifications )"* ! preventive control

.istorical data )"* ! preventive control

Functional testing ):* ! detective control

@eneral vehicle durability ):* ! detective control

DetectPrevent

R

P

N

D

E

T

O

C

C

S

E

V

ActionTaken

Action ResultsResponse &Target

Complete

Date

Recommended

Actions

R

P

N

De

t

ec

CurrentDesign

Controls

Oc

c

ur

PotentialCause(s!

"ec#anism(s

O$ %ailure

Cl

a

ss

S

e

v

Potential

E$$ect(s o$

%ailure

Potential

%ailure

"ode

tem

DetectPrevent

R

P

N

D

E

T

O

C

C

S

E

V

ActionTaken


Complete

Date

Recommended

Actions

R

P

N

De

t

ec

Current

Controls

Oc

c

ur

PotentialCause(s!

"ec#anism(s

O$ %ailure

Cl

a

ss

S

e

v

Potential

E$$ect(s o$

%ailure

%unction

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Examples of -ontrols

&ype 0 control! 9arnings which alert

product user to

impending failure

! Fail$safe features

! :esign

procedures$guidelines$

specifications

&ype = and B controls! Road test

! :esign Review

! Environmental test! fleet test

! lab test

! field test

! life cycle test! load test

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:etection

:etection values should correspond with A+A@% 7AE+f detection values are based upon internally defined criteria% a reference

must be included in FMEA to rating table with explanation for use:etection is the value assigned to each of the detective controls:etection values of 0 must eliminate the potential for failures due to design

deficiency

EKAM";EEngineering specifications ! no detection value.istorical data ! no detection valueFunctional testing ! detection B@eneral vehicle durability ! detection 2

DetectPrevent

RP

N

DE

T

OC

C

SE

V

ActionTaken


TargetComplete

Date

RecommendedActions

R

P

N

D

e

t

ec

CurrentDesign

Controls

O

c

c

ur

Potential

Cause(s!"ec#anism(s

O$ %ailure

C

l

a

ss

S

e

v

Potential

E$$ect(s o$

%ailure

Potential

%ailure

"ode

tem

DetectPrevent

RP

N

DE

T

OC

C

SE

V

ActionTaken


Complete

Date

RecommendedActions

R

P

N

D

e

t

ec

Current

Controls

O

c

c

ur

Potential

Cause(s!"ec#anism(s

O$ %ailure

C

l

a

ss

S

e

v

Potential

E$$ect(s o$

%ailure

%unction

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R"# )Ris/ "riority #umber*

Ris/ "riority #umber is a multiplication of the severity%

occurrence and detection ratings;owest detection rating is used to determine R"#

R"# threshold should not be used as the primary trigger fordefinition of recommended actions

EKAM";E

-annot see out of front window ! severity 1% ! incorrect ventlocation ! =% Functional testing ! detection B% R"# < 2L

DetectPrevent

R

P

N

D

E

T

O

C

C

S

E

V

ActionTaken


Complete

Date

Recommended

Actions

R

P

N

De

t

ec

CurrentDesign

Controls

Oc

c

ur

PotentialCause(s!

"ec#anism(s

O$ %ailure

Cl

a

ss

S

e

v

Potential

E$$ect(s o$

%ailure

Potential

%ailure

"ode

tem

DetectPrevent

R

P

N

D

E

T

O

C

C

S

E

V

ActionTaken


Complete

Date

Recommended

Actions

R

P

N

De

t

ec

Current

Controls

Oc

c

ur

PotentialCause(s!

"ec#anism(s

O$ %ailure

Cl

a

ss

S

e

v

Potential

E$$ect(s o$

%ailure

%unction

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Ris/ "riority #umber)R"#*

7everity x Cccurrence x :etection R"# is used to prioritize concerns$actions

&he greater the value of the R"# the greater theconcern

R"# ranges from 0

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R"# -onsiderations Rating scale example

! 7everity 03 indicates that the effect is very

serious and is worse than 7everity 05

! Cccurrence 03 indicates that the li/elihood

of occurrence is very high and is worse thanCccurrence 05

! :etection 03 indicates that the failure is not

li/ely to be detected before it reaches the end

user and is worse than :etection 05

1 5 10

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R"# -onsiderations (continued)

R"# ratings are relative to a particularanalysis5

!An R"# in one analysis is comparable to other

R"#s in the same analysis D

!D but an R"# may #C& be comparable to

R"#s in another analysis5

1 5 10

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R"# -onsiderations (continued)

8ecause similar R"#s can result in severaldifferent ways )and represent different types

of ris/*% analysts often loo/ at the ratings in

other ways% such as!Cccurrence$7everity Matrix )7everity and

Cccurrence*5

!+ndividual ratings and various ran/ing tables5

1 5 10

d d A i

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Recommended Actions

:efinition tas/s recommended for the purpose of

reducing any or all of the ran/ings

Cnly design revision can bring about a reduction in

the severity ran/ing

Examples of Recommended actions! "erform

:esigned experiments

reliability testing

finite element analysis

! Revise design

! Revise test plan

! Revise material specification

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Recommended Actions

All critical or significant characteristics must have

recommended actions associated with themRecommended actions should be focused on design% and

directed toward mitigating the cause of failure% or eliminating the

failure mode

+f recommended actions cannot mitigate or eliminate thepotential for failure% recommended actions must force

characteristics to be forwarded to process FMEA for process

mitigation

DetectPrevent

R

P

N

D

E

T

O

C

C

S

E

V

ActionTaken


Complete

Date

Recommended

Actions

R

P

N

De

t

ec

CurrentDesign

Controls

Oc

c

ur

PotentialCause(s!

"ec#anism(s

O$ %ailure

Cl

a

ss

S

e

v

Potential

E$$ect(s o$

%ailure

Potential

%ailure

"ode

tem

DetectPrevent

R

P

N

D

E

T

O

C

C

S

E

V

ActionTaken


Complete

Date

Recommended

Actions

R

P

N

De

t

ec

Current

Controls

Oc

c

ur

PotentialCause(s!

"ec#anism(s

O$ %ailure

Cl

a

ss

S

e

v

Potential

E$$ect(s o$

%ailure

%unction

Responsibility ( &arget -ompletion

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Responsibility ( &arget -ompletion

:ate

All recommended actions must have a person

assigned responsibility for completion of the action

Responsibility should be a name% not a title

"erson listed as responsible for an action must also be

listed as a team member

&here must be a completion date accompanying each

recommended action

DetectPrevent

R

P

N

D

E

T

O

C

C

S

E

V

ActionTaken


Complete

Date

Recommended

Actions

R

P

N

De

t

ec

CurrentDesign

Controls

Oc

c

ur

PotentialCause(s!

"ec#anism(s

O$ %ailure

Cl

a

ss

S

e

v

Potential

E$$ect(s o$

%ailure

Potential

%ailure

"ode

tem

DetectPrevent

R

P

N

D

E

T

O

C

C

S

E

V

ActionTaken


Complete

Date

Recommended

Actions

R

P

N

De

t

ec

Current

Controls

Oc

c

ur

PotentialCause(s!

"ec#anism(s

O$ %ailure

Cl

a

ss

S

e

v

Potential

E$$ect(s o$

%ailure

%unction

Action Results

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Action Results

6nless the failure mode has been eliminated% severity

should not changeCccurrence may or may not be lowered based upon the

results of actions

:etection may or may not be lowered based upon theresults of actions

+f severity% occurrence or detection ratings are notimproved% additional recommended actions must to bedefined

DetectPrevent

R

P

N

D

E

T

O

C

C

S

E

V

ActionTaken


Complete

Date

Recommended

Actions

R

P

N

De

t

ec

CurrentDesign

Controls

Oc

c

ur

PotentialCause(s!

"ec#anism(s

O$ %ailure

Cl

a

ss

S

e

v

Potential

E$$ect(s o$

%ailure

Potential

%ailure

"ode

tem

DetectPrevent

R

P

N

D

E

T

O

C

C

S

E

V

ActionTaken


Complete

Date

Recommended

Actions

R

P

N

De

t

ec

Current

Controls

Oc

c

ur

PotentialCause(s!

"ec#anism(s

O$ %ailure

Cl

a

ss

S

e

v

Potential

E$$ect(s o$

%ailure

%unction

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Exercise :esign FMEA

"erform A :FMEA on a pressure coo/er

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Pressure Cooer Safety Features

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Pressure Cooer Safety Features

05 7afety valve relieves pressure before itreaches dangerous levels5

=5 &hermostat opens circuit through heating

coil when the temperature rises above =23S-5

B5 "ressure gage is divided into green and

red sections5 T:angerT is indicated when thepointer is in the red section5

Pressure Cooer F!EA

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Pressure Cooer F!EA

:efine 7cope

05 Resolution < &he analysis will be

restricted to the four maHor subsystems

)electrical system% safety valve% thermostat%and pressure gage*5

=5 Focus < 7afety

"ressure coo/er bloc/ diagram

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"ressure coo/er bloc/ diagram

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"rocess FMEA

:efinition!A documented analysis which begins with a

teams thoughts concerning re'uirements thatcould go wrong and ending with definedactions which should be implemented to help

prevent and$or detect problems and theircauses5

!A proactive tool to identify concerns with thesources of variation and then define and ta/ecorrective action5

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"FMEA as a toolD

&o access ris/ or the li/elihood ofsignificant problem

&rouble shoot problems

@uide improvement aid in determining

where to spend time and money

-apture learning to retain and share

/nowledge and experience

Customer Re'uirements

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Customer Re'uirements

Deign Speci$ications

e) Product C#aracteristics

"ac#ine Process Capa*ilit)

Process%lo+

Diagram

Process %"EAProcessControl

Plan

Operator,o*

nstructions

Con$orming Product

Reduced Variation

Customer Satis$action

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+nputs for "MEA

"rocess flow diagram

Assembly instructions

:esign FMEA

-urrent engineering drawings and specifications :ata from similar processes

! 7crap

!Rewor/! :owntime

! 9arranty

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"rocess Function Re'uirement

8rief description of the manufacturingprocess or operation

&he "FMEA should follow the actual wor/

process or se'uence% same as the processflow diagram

8egin with a verb

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&eam Members for a "FMEA

"rocess engineer Manufacturing supervisor

Cperators

Quality 7afety

"roduct engineer

-ustomers 7uppliers

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"FMEA Assumptions

&he design is valid

All incoming product is to design

specifications

Failures can but will not necessarily occur

:esign failures are not covered in a

"FMEA% they should have been part of the

design FMEA

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"otentional Failure Mode

.ow the process or product may fail tomeet design or 'uality re'uirements

Many process steps or operations will have

multiple failure modes &hin/ about what has gone wrong from past

experience and what could go wrong

il d

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-ommon Failure Modes

Assembly! Missing parts

! :amaged

! Crientation

! -ontamination

! Cff location

&or'ue

! ;oose or over tor'ue! Missing fastener

! -ross threaded

Machining! &oo narrow

! &oo deep

! Angle incorrect

! Finish not to

specification

! Flash or not cleaned

i l f il d

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"otentional failure modes

7ealant! Missing

! 9rong material

applied

! +nsufficient or

excessive material

! dry

:rilling holes! Missing

! ;ocation

! :eep or shallow

! Cver$under size

! -oncentricity

! angle

" i l ff

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"otential effects

&hin/ of what the customer will experience!End customer

!#ext user

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"otential Effects

End user!#oise

! ;ea/age

! Cdor

! "oor appearance

! Endangers safety

! ;oss of a primary

function!performance

#ext operation! -annot assemble

! -annot tap or bore

! -annot connect

! -annot fasten

! :amages e'uipment

! :oes not fit

! :oes not match! Endangers operator

7 i R /i

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7everity Ran/ing .ow the effects of a potential failure mode may

impact the customer Cnly applies to the effect and is assigned with

regard to any other rating

"otential effects offailure

7everity

-annot assemblebolt)2*

Endangersoperator)03*

Jibration )4*

03

&a/e the highest effectran/ing

-l ifi i

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-lassification

6se this column to identify any re'uirementthat may re'uire additional process control

!UV-U < /ey characteristic

!UFU ! fit or function!U7U < safety

!Pour company may have a different symbol

" t ti l -

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"otential -auses

-ause indicates all the things that may beresponsible for a failure mode5

-auses should items that can have actioncompleted at the root cause level )controllable in

the process* Every failure mode may have multiple causeswhich creates a new row on the FMEA

Avoid using operator dependent statements i5e5operator error use the specific error such asoperator incorrectly located part or operatorcross threaded part

" t ti l -

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"otential -auses

E'uipment! &ool wear

! +nade'uate pressure

! 9orn locator

! 8ro/en tool

! @auging out of

calibration

! +nade'uate fluid levels

Cperator! +mproper tor'ue

! 7elected wrong part

! +ncorrect tooling

! +ncorrect feed or speed

rate

! Mishandling

! Assembled upsidedown

! Assembled bac/wards

C R /i

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Cccurrence Ran/ing

.ow fre'uent the cause is li/ely to occur

6se other data available

!"ast assembly processes

!7"-

!9arranty

Each cause should be ran/ed according to

the guideline

- t " - t l

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-urrent "rocess -ontrols

All controls should be listed% but ran/ing shouldoccur on detection controls only

;ist the controls chronologically

! :on not include controls that are outside of your plant :ocument both types of process controls

! "reventative< before the part is made

"revent the cause% use error proofing at the source

! :etection< after the part is made :etect the cause )mista/e proof*

:etect the failure mode by inspection

" - t l

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"rocess -ontrols

"reventative! 7"-

! +nspection verification

! 9or/ instructions

! Maintenance

! Error proof by design

! Method sheets

! 7et up verification! Cperator training

:etection! Functional test

! Jisual inspection

! &ouch for 'uality

! @auging

! Final test

: t ti

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:etection

"robability the defect will be detected byprocess controls before next or subse'uentprocess% or before the part or componentleaves the manufacturing or assemblylocation

;i/ely hood the defect will escape themanufacturing location

Each control receives its own detectionran/ing% use the lowest rating for detection

Ri / " i it # b )R"#*

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Ris/ "riority #umber )R"#*

R"# provides a method for a prioritizingprocess concerns

.igh R"#,s warrant corrective actions

:espite of R"#% special considerationshould be given when severity is high

especially in regards to safety

R"# f i /

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R"# as a measure of ris/

An R"# is li/e a medical diagnostic%predicting the health of the patient

At times a persons temperature% blood

pressure% or an EV@ can indicate potentialconcerns which could have severe impacts

or implications

R d d ti

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Recommended actions

Control

n$luence

Can-t control or in$luence at t#is time

Recommended Action

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Recommended Action

:efinition tas/s recommended for thepurpose of reducing any or all of theran/ings

Examples of Recommended actions!"erform "rocess instructions )"*

&raining )"*

-an,t assemble at next station ):* Jisual +nspection ):*

&or'ue Audit ):*

P"EA as a n$o 0u*

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Process %"EA document

Process

Control

Plan

Operator

,o*

nstructions

Process

%lo+

Diagram

Process

C#anges

Current or

E.pected

'ualit)

per$ormance

Customer

Design

re'uirements

mplementation

and veri$ication

Recommended

Corrective actions

i/e/

Error proo$ing

Continuous mprovement E$$orts

And RPN reduction loop

Communication o$ standard

o$ +ork to operators

FMEA process flow

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"rocess FMEA exercise

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"rocess FMEA exercise

&as/ "roduce and mail sets of contributionre'uests for 8reast -ancer research

Cutcome "rofessional loo/ing re'uests to

support research for a cure% 23 sets ofinformation% contribution re'uest% and

return envelope

Re'uirements

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Re'uirements

#o inHury to operators or users Finished dimension fits into envelope All items present )info sheet% contribution form% and return envelope*

WVEPX All pages in proper order )info sheet% contribution form% return

envelope* WVEPX

#o tattered edges #o dog eared sheets +tems put together in order )info sheet Yfolded to fit in legal envelopeZ%

contribution sheet% return envelope* WVEPX @eneral overall neat and professional appearance

"roper first class postage on envelopes 8reast cancer seal on every envelope sealing the envelope on the bac/ Mailing label% stamp and seal on placed s'uarely on envelope WVEPX Rubber band sets of =2

"rocess steps

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Fold information sheet to fit in legalenvelope

-ollate so each group includes all

components 7tuff envelopes

Affix address% postage% and seal

Rubber bands sets of =2 :eliver to post office for mail today by 2

pm

03 steps to conduct a FMEA

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03 steps to conduct a FMEA

05 Review the design or process=5 8rainstorm potential failure modes

B5 ;ist potential failure effects

L5 Assign 7everity ratings

25 Assign Cccurrence ratings45 Assign detection rating

>5 -alculate R"#

?5 :evelop an action plan to address high R"#,s

15 &a/e action035 Reevaluate the R"# after the actions are completed

Reasons FMEA,s fail

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Reasons FMEA s fail

05 Cne person is assigned to complete the FMEA5=5 #ot customizing the rating scales with company specific

data% so they are meaningful to your company

B5 &he design or process expert is not included in theFMEA or is allowed to dominate the FMEA team

L5 Members of the FMEA team are not trained in the use ofFMEA% and become frustrated with the process

25 FMEA team becomes bogged down with minute detailsof design or process% losing sight of the overall obHective

Reasons FMEA,s fail

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Reasons FMEA s fail

45 Rushing through identifying the failure modes tomove onto the next step of the FMEA

>5 ;isting the same potential effect for every failure

i5e5 customer dissatisfied5

?5 7topping the FMEA process when the R"#,s are

calculated and not continuing with the

recommended actions5

15 #ot reevaluating the high R"#,s after thecorrective actions have been completed5

7oftware Recommendations

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7oftware Recommendations

#umerous types and specialized formats Many have free trials

!K

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PotpourriPotpourriMethodsMethods RankingsRankingsSODSOD

$200

$300

$400

$500

$100

$200

$300

$400

$500

$100

$200

$300

$400

$500

$100

$200

$300

$400

$500

$100

unit-2 - fmea

Documents