process fmea 071806

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Failure Mode Effects

Analysis(FMEA)

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Provide insight to the uses of FMEA

Define different types of FMEA

Learn the steps to develop a Process

FMEA

Review FMEA Audit Form

Practice creating an FMEA

Objectives

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What is an FMEA?

A structured approach to:

Identifying the ways in which a product or process can failEstimating the risk to the customer associated with specific causes

Prioritizing the actions that should be taken to reduce the risk to thecustomer

For Example, a process FMEA will:

Capture the critical process inputs

Identify the ways the product or process can fail because of these inputs

Facilitate the documentation of a recommended action plan to preventthose failures

Be used to initially evaluate the control plan

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Current standard is SAE J-1739

History of the FMEA

First used in the 1960s in the Aerospace

industry during the Apollo program to mitigaterisk during missions

In 1974 the U.S. Navy developed

MIL-STD-1629 regarding the use ofthe FMEA

In the late 1970s the automotive

industry began to incorporate FMEA intothe management of their processes dueto increasing liability costs
http://../

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Types of FMEAs

System

Used to analyze systems and sub-systems in the early conceptand design stages. Focuses on potential failure modes associatedwith the functions of a system caused by the design.

Design

Used to analyze product designs before they are released toproduction. A DFMEA should always be completed well in advanceof a prototype build. Focuses on product function.

Process

Used to analyze manufacturing, assembly, or any otherprocesses. Focuses on process inputs.

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Definition of FMEA Terms

Failure Mode

Effect

Cause

Current Controls

Severity, Occurrence, Detection

Risk Priority Number (RPN)

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Definition of Terms

EffectDefinition

Impact on customer requirements

Generally an external customer focus, but can alsoinclude downstream processes

Examples

Temperature too high: paint cracks

Incorrect PO number: accounts receivable traceabilityerrors

Surface contamination: poor adhesion

Dropped call: customer dissatisfaction

Paint too thin: poor coverage

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Definition of Terms

CauseDefinition

Sources of process variation that cause the failure mode tooccur

Identification of causes starts with failure modes

associated with the highest severity ratingsExamples

Temperature too high: thermocouple out of calibration

Incorrect PO number: typorgaphikal error

Surface contamination: overhead hoist systems

Dropped call: insufficient number of CS representatives

Paint too thin: high solvent content

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Definition of Terms

Current Controls

Definition

Systematized methods / devices in place to prevent ordetect failure modesor causes(before causing effects)

Prevention consists of failsafing, automated control andpreventive maintenance

Controls consist of audits, checklists, inspection,laboratory testing, training, SOPs, setup verifications, etc.

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Definition of Terms

Severity (of Effect)

(1=Not Severe, 10=Very Severe) Importance of effect on

customer requirements Could also be concerned

with safety and other risksif failure occurs

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Definition of Terms

Occurrence (of Cause)(1=Not Likely, 10=Very Likely)

Frequency with which a given cause occurs and createsfailure mode(s)

Can sometimes refer to the frequency of a failure mode

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Definition of TermsDetection (Capability of Current Controls)

(1=Likely to Detect, 10=Not Likely at all to Detect)

Ability of current control scheme to detect or prevent: the causes before creating failure mode the failure modes before causing effect

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Definition of Terms

Risk Priority Number (RPN)

Definition

The output of an FMEA

A calculated number based on information you provide,

regarding:

potential failure modes,

effects, and

current ability of the process to detect the failures beforereaching the customer

Calculated as the product of three quantitative ratings, each onerelated to the effects, causes, and controls:

RPN = Severity x Occurrence x Detection

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FMEA Form - Initial Assessment

Process

Step/InputPotential Failure Mode Potential Failure Effects

S

E

V

Potential Causes

O

C

C

Current Controls

D

E

T

R

P

N

Actions

Recommended

What is the

process step/

Input under

investigation?

In what ways does the Key

Input go wrong?

What is the impact on the Key

Output Variables (Customer

Requirements) or internal

requirements?

How

Severeisthe

effecttothe

cusotmer?What causes the Key Input to

go wrong?

How

oftendoescause

orFMo

ccur?What are the existing controls and

procedures (inspection and test)

that prevent eith the cause or the

Failure Mode? Should include an

SOP number.

How

wellcanyou

de

tectcauseorFM? What are the actions

for reducing the

occurrance of the

Cause, or improving

detection? Should

have actions only on

high RPN's or easyfixes.

0

0

0

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FMEA Form - Long Term History

Current Controls

D

E

T

R

P

N

Actions

RecommendedResp. Actions Taken

S

E

V

O

C

C

D

E

T

R

P

N

What are the existing controls and



Failure Mode? Should include anSOP number.

Howw

ellcanyou

detectcau

seorFM? What are the actions

for reducing the

occurrance of the

Cause, or improvingdetection? Should


high RPN's or easy

fixes.

Whose

Responsible

for the

recommendedaction?

What are the completed

actions taken with the

recalculated RPN? Be

sure to includecompletion month/year

0 0

0 0

0 0

0 0

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1. For each process input, determine the ways inwhich the input can go wrong (failure modes)

Process

Step

Key Process

Input

Failure Modes -What can go

wrong? Effects Causes

Paint Nozzle type Nozzle too large

Nozzle too small

Dirty nozzle

FMEA - Step by Step

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2. For each failure mode associated with the

inputs, determine effectsThese effects are internal requirements for the next processand / or to the final customer.

ProcessStep

Key ProcessInput

Failure Modes -

What can gowrong? Effects Causes

Paint Nozzle type Nozzle too largeToo much paint,

splatter

Nozzle too smallToo little paint,

low rate

Dirty nozzle

Uneven spray

pattern, too little

paint

FMEA - Step by Step

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Process

Step

Key Process

Input



Current

Controls

Paint Nozzle type Nozzle too large Too much paint,splatter

Incorrect nozzle inparts bin

Nozzles receivedbagged and tagged


low rate

Incorrect P/N in

procedureSOP #XXXXX

Dirty nozzle

Uneven spray

pattern, too little

paint

Nozzle not kept in

solventNone

4. List the current controls for each cause

For each failure mode / cause, list how the cause is preventedor the

failure mode is detected.

Reference documented procedures and instructions where they exist.

This is how the FMEA identifies initial gaps in the current ControlPlan. Process teams can start working on these gaps right away.

FMEA - Step by Step

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Process

Step

Key Process

Input



Current

Controls

Paint Nozzle type Nozzle too largeToo much paint,

splatter

Incorrect nozzle in

parts bin

Nozzles received

bagged and tagged


low rate

Incorrect P/N in

procedure

Paint set-up SOP

#XXXXX

Dirty nozzle

Uneven spray

pattern, too little

paint

Nozzle not kept in

solventNone

Paint Paint viscosity Viscosity too high

Paint spatter,

low rate, high

paint usage

Temperature too

low in booth

Closed loop HVAC

controls

Viscosity too lowThin paint, high

solvent usage

Incorrect solvent

loading

Mixing procedure

SOP #XXXXX

Heres the rest of the example

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5. Create severity, occurrence, and detection rating scales

Example Rating ScaleRating Severity of Effect Likelihood of Occurrence Ability to Detect

10 Hazardous without warningVery high:

Cannot detect

9 Hazardous with warningFailure is almost inevitable

Very remote chance of detection

8 Loss of primary functionHigh:

Remote chance of detection

7Reduced primary function

performance

Repeated failuresVery low chance of detection

6 Loss of secondary functionModerate:

Low chance of detection

5Reduced secondary function

performance

Occasional failuresModerate chance of detection

4Minor defect noticed by most

customers

Moderately high chance of

detection

3Minor defect noticed by some

customers Low:High chance of detection

2Minor defect noticed by

discriminating customers

Relatively few failuresVery high chance of detection

1 No effect Remote: Failure is unlikely Almost certain detection

FMEA - Step by Step

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6. Assign severity, occurrence and detection ratings to

each cause

Use only one severity value for each effect

Determine which effect has the highest associated severityand use that SEV value for ALL causes for the related

failure mode Example: If a failure mode could cause either a

scratched surface (SEV 3) or an incorrect dimension(SEV 9), then use a SEV of 9 for all lines in that failuremode

FMEA - Step by Step

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6. Assign severity, occurrence and detectionratings to each cause

Process


S

E

V

Potential Causes

O

C

C

Current Controls

D

E

T

R

P

N

Paint / Nozzle

type

Nozz le too large Too much paint, splatter

7

Incorrect nozzle in parts bin

4

Nozzles received bagged and

tagged 7 196

Nozzle too small Too little paint, low rate8

Incorrect P/N in procedure2

Paint set-up SOP #XXXXX5 80

Dirty nozzle Uneven spray pattern, too

little paint 7Nozzle not kept in solvent

8None

10 560

Paint / Paint

viscosity

Viscosity too high Paint spat ter, low rate, high

paint usage 7Temperature too low in booth

2Closed loop HVAC controls

2 28

Viscos ity too low Thin paint, high solvent

usage 8Incorrect solvent loading

6Mixing procedure SOP #XXXXX

4 192

FMEA - Step by Step

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7. Calculate RPNs

Multiply the severity, occurrence, and detection values foreach line in the FMEA.

Sort all failure modes by RPN. Notice that all cells have to beidentified to carry the failure modes, effects, causes andcurrent controls along with the sort.

Process


S

E

V

Potential Causes

O

C

C

Current Controls

D

E

T

R

P

N

Paint / Nozzle

type


little paint 7Nozzle not kept in solvent

8None

10 560

Paint / Nozzle

type

Nozzle too large Too much paint, splatter7

Incorrect nozzle in parts bin4

Nozzles received bagged and

tagged 7 196

Paint / Paint

viscosity

Viscosity too low Thin paint , high solvent

usage 8Incorrect solvent loading

6Mixing procedure SOP #XXXXX

4 192

Paint / Nozzle

type


Incorrect P/N in procedure2

Paint set-up SOP #XXXXX5 80

Paint / Paint

viscosity

Viscosity too high Paint spatter, low rate, high

paint usage 7Temperature too low in booth

2Closed loop HVAC controls

2 28

FMEA - Step by Step

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RPN Review

Calculate the RPN for each effect / cause / controlscombination and review the results, looking for insights

Do the gut check. Does the Pareto of items makesense?

If not, maybe the ratings given are varying.

Determine potential next steps:

Data collection

Experiments

Process improvements

Process control implementations

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8. Determine recommended actions to reduce

high RPNs

Now fill in recommended actions for top RPNs.

Actions are recommended for only the high RPNs.

The key is FOCUS!

Process

Step/Input

Potential Failure

ModePotential Failure Effects

S

E

V

Potential Causes

O

C

C

Current Controls

D

E

T

R

P

N

Actions

RecommendedResp.

Paint / Nozzle

type


little paint 7Nozzle not kept in

solvent 8None

10 560Design nozzle storage

system

PTBNL

Paint / Nozzle

type

Nozzle too large Too much paint, splatter7

Incorrect nozzle in parts

bin 4Nozzles received bagged

and tagged 7 196Review and improve

part specifications

SQA

Paint / Paint

viscosity

Viscosity too low Thin paint, high solvent

usage 8

Incorrect solvent loading

6

Mixing procedure SOP

#XXXXX 4 192

Review and improve

training and mixing

methods

Paint / Nozzle

type


Incorrect P/N in

procedure 2Paint set-up SOP #XXXXX

5 80

Paint / Paint

viscosity

Viscosity too high Paint spatter, low rate,

high paint usage 7Temperature too low in

booth 2Closed loop HVAC

controls 2 28

FMEA - Step by Step

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9. Take appropriate actions and recalculate

RPNs

Potential Causes

O

C

C

Current Controls

D

E

T

R

P

N

Actions


S

E

V

O

C

C

D

E

T

R

P

N

Nozzle not kept in

solvent 8None

10 560Design nozzle storage

system

PTBNL Implemented automatic

nozzle 'parking' system 7 3 4 84

Incorrect nozzle in parts

bin 4Nozzles received bagged

and tagged 7 196Review and improve

part specifications

SQA Standardized on single

nozzle 7 2 7 98

Incorrect solvent loading

6

Mixing procedure SOP

#XXXXX 4 192

Review and improve

training and mixing

methods

XYZ Improved mixing

procedures and

equipment

8 4 4 128

Incorrect P/N in

procedure 2

Paint set-up SOP #XXXXX

5 80 0

Temperature too low in

booth 2Closed loop HVAC

controls 2 28

0

FMEA - Step by Step

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Summary

Process


S

E

V

Potential Causes

O

C

C

Current Controls

D

E

T

R

P

N

Actions

Recommended

0 0 0 0

0 0 0 0

0 0 0 0

0 0 0 0

0 0 0 0

Whatis theInput

Whatcan gowrong

with theInput?

What can

be done?

What isthe Effect

on theOutputs?

What arethe

Causes?

How arethese found

orprevented?

HowBad?

HowOften?

Howwell?

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1 Does the Header Contain Adequate Information ?

Yes E

No

1aName of Program(s) included? N/A

1bName of Supplier included? N/A

1c Part Number and Description included? N/A

1d

Core Team includes all names with title or area? Note: Phone #'s recommended, but not mandatory for this audit. N/A

1eKey Date Shown is Cummins VPI Program Beta Build Date? N/A

1fFMEA Date (Orig.) is shown? N/A

1gFMEA "(Rev.)" date within past 60 days? Note: "N/A" if "(Orig.)" date is within 60 days. N/A

1hAll else ok (no other issues)? N/A

If all answers "Yes," check "Yes." If one or more "No," check "No." N/A

Note: "E" means only minor "E"xceptions, see comment section..

PFMEA Audit

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2 Is the Process Function/Requirements Column Adequate? Yes E No

2aEach operation is (briefly) described using a verb/noun (bend tube, apply primer, pierce hole, etc.), rather than justnumbered?

2bCharacteristics of part/process listed (hole diameter, tube length, etc.)? Note: Including specification tolerances (25mm. +/- 2) are recommended, but not required for this audit.

2cAll else ok (no other issues)?

If all answers "Yes," check "Yes." If one or more "No," check "No." Otherwise, check "E"

3 Potential Failure Modes Column Adequate? Yes E No

3aFailure Modes written in terms of a characteristic (hole dia., surf. roughness)?

3bFailure Modes are specific ("hole dia. too small" rather than "hole out of spec.")?



PFMEA Audit

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4 Potential Effects of Failure Column Adequate? Yes E No

4aEffects written in terms of what customer (downstream process or end user) will notice/experience ("unable toassemble" do not use "scrap")?

4bAll else ok (no other issues)?


5 Severity Yes E No

5aSeverity rankings not underratedbased on AIAG Manual criteria? Note: Overrating not recommended, but notrequirement for this audit.

5bSeverity rankings identical for identical Potential Effects?



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6 Class Yes E No

6aAre all Key, Major or Critical characteriustics identified?

6bAll else ok (no other issues)?


Supplier Process FMEA: Audit Summary-Page 2

7 Potential Causes Column Adequate? Yes E No7a

Descriptions specific? Note: 1) "Incorrect set-up", "improper cooling", etc. must be replaced by or include specificdescription of what was "incorrect" (temp. set too high) or "improper" (time too short). 2) Replace "operatorerror" with "operator installed widget upside down."

7b All else ok (no other issues)?


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8 Occurrence Yes E No

8a There is one Occurrence ranking for each cause ("worn/broken tool" must have two separate rankings)?

8b All else ok (no other issues)?


9 Current Controls Column Adequate? Yes E No

9a

Controls correctly identified as either Detection ("D") (Mistake Proof, 100% visual insp., etc.) or Prevention ("P")(visual aids, training, PM, etc.) controls? Note: 1) separate set-up process (P.) from 1st piece inspect. (D.). 2)

Error-Proofing is preventive (can't make), but may be listed as "P" or "D" or both.

9b Controls are adequately explained or easily referenced?

9c All else ok (no other issues)?


PFMEA Audit

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10 Detection Yes E No

10a One Detection ranking for each Occurrence ranking?

10b

Detection ranking consistent with AIAG Manual (Visual Inspection=8, etc.)? Note: Detection ranking is no betterthan the best detection method (SPC + visual inspection + hourly audit=6 [SPC is best]).



11 Recommended Actions & Responsibility Columns Reasonable? Yes E No

11aDo all Severity rankings of 9 or 10 with a Detection ranking greater than 3 have a Recommended Action which will

lower the Detection? Notes: 1) "None" only to be used if Detection ranking is less than 4. 2) Justification for"None" in this column recommended, but not mandatory for this audit.

11b Recommended Actions are assigned to a specific person (not a department)?

11c Target Completion dates are shown and not past due?

11d All else ok (no other issues)?


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12 Action Results Effectively Executed? Yes E No

12a Re-rankings affected Occurrence and/or Detection (not Severity)?

12b Occurrence and/or Detection re-rankings consistent with AIAG Manual?



PFMEA Audit

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Lets Create a PFMEA

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FMEA Form - Initial AssessmentProcess


S

E

V

Potential Causes

O

C

C

Current Controls

D

E

T

R

P

N

Actions

Recommended

What is the

process step/

Input under

investigation?

In what ways does the Key

Input go wrong?

What is the impact on the Key

Output Variables (Customer

Requirements) or internal

requirements?

How

Severeisthe

effecttothe

cusotmer?What causes the Key Input to

go wrong?

How

oftendoescause

orFMo

ccur?What are the existing controls and




SOP number.

How

wellcanyou

detectcauseorFM? What are the actions

for reducing the

occurrance of the

Cause, or improving

detection? Should


high RPN's or easy

fixes.

0

0

0

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FMEA Form - Long Term History

Current Controls

D

E

T

R

P

N

Actions


S

E

V

O

C

C

D

E

T

R

P

N

What are the existing controls and




SOP number.

Howw

ellcanyou

detectca

useorFM? What are the actions

for reducing the

occurrance of the

Cause, or improving

detection? Should


high RPN's or easy

fixes.

Whose

Responsible

for the

recommended

action?

What are the completed

actions taken with the

recalculated RPN? Be

sure to include

completion month/year

0 0

0 0

0 0

0 0

process fmea 071806

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