Fmea Training

Failure Mode and Effects Analysis (FMEA)

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Sequence of System Drawings and Specification

Feasibility Study

Process Flow Diagram

Process FMEA

Control Plan

Process Sheet and Work Instruction 2

What Is An FMEA? FMEA is a systematic analytical, logical & progressive potential failure analysis technique (a paper test) that combines the technology and experience of several engineering disciplines in identifying foreseeable failure modes of a product / process/ system and service and planning for its elimination.

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Types of FMEA •System FMEA (System / Sub system / Component) •Design FMEA (System/Sub System / Component) •Process FMEA •Service FMEA •Machines •Human Resources

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POTENTIAL FAILURE MODE AND EFFECT ANALYSIS (PROCESS FMEA)

FMEA NUMBER

ITEM

PROCESS RESPONSIBILTY

PAGE

MODEL YEAR(S) / VEHICLE(S)

KEY DATE

PREPARED BY FMEA DATE(ORIG.)

CORE TEAM

Item / Process Step Function

OF

Potential Failure Mode

Potential Effect(s) of Failure

S e v

C l a s s

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

O c c u r

Current Process Controls Prevent Detect

D e t e c

R P N

Response & Recommended Traget Actions Complete Date

Action Results Action Taken

S E V

O C C

D E T

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R P N

FMEA Preparation Vertical Approach – Key Elements of Efficient Development – Identify all functions/process steps – Identify all failure modes via brainstorming/data/warranty/COQ – Identify all effects via brainstorming/data • Customer focus

– Develop data pools for • Failure Modes, Effects and Causes for future/ faster FMEA development

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System/Subsystem/ Design FMEA – Effect • Customer view/customers words • Regulation violation • Level of dissatisfaction

– Consider All Customers • • • • •

End User Engineering Community Manufacturing Community (Operators/Employees) Regulatory Body

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Severity Column Item / Process Step Function

Potential Failure Mode

Potential Effect(s) of Failure

S e v

C l a s s

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

O c c u r

Current Process Controls Prevent Detect

D e t e c

R P N

Response & Recommended Traget Actions Complete Date

Action Results Action Taken

S E V

O C C

D E T

Severity Column

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R P N

Severity Column An assessment of the seriousness of the effect to - The next level of operation - Assembly operation - End User ( Final Customer) •Applies to the effect and effect only •Severity expressed as a number on a scale of 1 to 10 •A reduction in severity ranking can be achieved only through a product or process design change.

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AUTOMOTIVE EXAMPLE SEVERITY EVALUATION CRITERIA Effect

Criteria: Severity of Effect The ranking results a potential failure mode results in a final customer and/or a manufacturing/assembly plant defect. The final customer should always be considered first. If both occur, use the higher of the two severities. (Customer Effect)

Criteria: Severity of Effect The ranking results a potential failure mode results in a final customer and/or a manufacturing/assembly plant defect. The final customer should always be considered first. If both occur, use the higher of the two severities. (Manufacturing/Assembly Effect )

Hazardous without warning

Very high severity ranking when a potential failure mode affects safe vehicle operation and/or involves noncompliance with government regulation without warning.

Or may endanger operator (machine or assembly) without warning.

10

Hazardous with warning

Very high severity ranking when a potential failure mode affects safe vehicle operation and/or involves noncompliance with government regulation with warning.

Or may endanger operator (machine or assembly) with warning.

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Very high

Vehicle/Item inoperable (loss of primary function)

Or 100% of product may have to be scrapped, or vehicle/item repaired in repair department with a repair time greater than one hour.

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High

Vehicle/Item operable, but at reduced level of performance, Customer very dissatisfied.

Or Product may have to be sorted and a portion (less than 100%) scrapped, or vehicle/item repaired in repair department with a repair time between a half-hour and an hour.

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Moderate

Vehicle/Item operable, but comfort/Convenience item(s) inoperable Customer dissatisfied.

Or a portion (less than 100%) of the product may have to be scrapped with no sorting, or vehicle/item repaired in repair department with a repair time less than a half-hour.

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Low

Vehicle/Item operable, but comfort/Convenience item(s) inoperable at a reduced level of performance. Customer somewhat dissatisfied.

Or 100% of product may have to be reworked, or vehicle/item repaired offline but does not got to repaire department.

5

Very Low

Fit & Finish/Squeak & Rattle item does not conform. Defect noticed by most customers (greater than 75%)

Or the product may have to be sorted, with no scrap, and a portion (less than 100%) reworked.

4

Minor

Fit & Finish/Squeak & Rattle item does not conform. Defect noticed by 50% of customers

Or a portion (less than 100%) of the product may have to be reworked, with no scrap , on-line but out of station.

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Very Minor

Fit & Finish/Squeak & Rattle item does not conform. Defect noticed by discriminating customers (less than 25%)

Or a portion (less than 100% of the product may have to be reworked, with no scrap, on-line but in-station.

2

None

No discernible effect.

Or slight inconvenience to operation or operator, or no effect.

R anki ng

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Classification And Definition Column Item

Function

Potential Failure Mode

Potential Effect(s) of Failure

S e v

C O Potential l c Cause(s) / a c Mechanism(s) s u of Failure s r

Current Design Controls

D Response & e R. Recommended Target t P. Actions Complete e N. Date c

Action Results Actions Taken

S e v

O c c

Classification and Definition Column

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D R. e P. t N.

Failure Mode/Cause Relationship In Different FMEA Levels Inadequate Electrical Connection

Cause

Failure Mode

Failure Mode Motor Stops

Inadequate Electrical Connection

Inadequate Causes Harness Locking Too Short Feature 12

Potential Causes of Failures – A identification of a design weakness – A root cause, not a symptom – Actionable, corrective action pointed at this weakness can reduce the risk – Carryout root cause analysis as a separate exercise before listing the causes using Cause and effect Analysis. – Continue through all failure modes. – Note that many causes are recurring. 13

Occurrence Column Item / Process Step Function

Potential Failure Mode

Potential Effect(s) of Failure

S e v

C l a s s

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

O c c u r

Current Process Controls Prevent Detect

D e t e c

R P N

Response & Recommended Traget Actions Complete Date

Action Results Action Taken

S E V

O C C

D E T

Occurrence Column

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R P N

Occurrence Evaluation Criteria SUGGESTED OCCURRENCE EVALUATION CRITERIA Probability of Failure

Very High: Persistent failures

High: Frequent failures

Moderate: Occasional failures

Low: Relatively few failures Remote: Failure is unlikely

Likely Failure Rates Over Design Life

Ranking

≥ 100 per thousand vehicles/items

10

50 per thousand vehicles/items

9

20 per thousand vehicles/items

8

10 per thousand vehicles/items

7

5 per thousand vehicles/items

6

2 per thousand vehicles/items

5

1 per thousand vehicles/items

4

0.5 per thousand vehicles/items

3

0.1 per thousand vehicles/items

2

≤ 0.01 per thousand vehicles/items

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*Note: Zero (0) rankings for Severity, Occurrence or Detection are not allowed

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Occurrence Rating – If an action would effectively eliminate the possibility of the cause occurring, the action is listed as described earlier. • Occurrence of 1 or 2 require proof using a surrogate product or mistake proofing.

DATA

HARD FACTS

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Example of Significant/ Critical SpecialThreshold Characteristics Matrix S E V E R I T Y

10 9 8 7 6 5 4 3 2 1

POTENTIAL CRITICAL CHARACTERISTICS Safety/Regulatory POTENTIAL SIGNIFICANT CHARACTERISTICS Customer Dissatisfaction

ANOYANCE ZONE ALL OTHER CHARACTERISTICS Appropriate actions / controls already in place

1

2

3 4 5 6 7 8 9 10 OCCURRENCE

*Used by permission of Ford Motor Company

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Detection Rating Detection

Criteria

Inspection Types A

B

Suggested Range of Detection Methods

Ranking

C

Almost Impossible

Absolute certainly of non- detection

X

Cannot detect or is not checked.

10

Very Remote

Controls will probably not detect

X

Control is achieved with indirect and random checks only.

9

Remote

Controls have poor chance of detection.

X

Control is achieved with Visual Inspection only.

8

Very Low

Controls have poor chance of detection.

X

Control is achieved with double visual inspection only

7

Low

Controls may detect

X

X

Control is achieved with charting methods, such as SPC (Statistical Process Control.)

6

Moderate

Controls may detect

X

Control is based on variable gauging after parts have left the station, or Go/No Go gauging performed on 100% of the parts after parts have left the station.

5

Moderately High

Controls have a good chance to detect

X

X

Error detection in subsequent operations, OR gauging performed on setup and first piece check (for set-up causes only.)

4

High

Controls have a good chance to detect

X

X

Error detection in-station, or error detection in subsequent operations by multiple layers of acceptance: supply, select, install, verify. Cannot accept discrepant part.

3

Very High

Controls almost certain to detect.

X

X

Error detection in-station (automatic gauging with automatic stop feature). Cannot pass discrepant part..

2

Very High

Controls certain to detect.

X

Discrepant parts cannot be made because item has been error-proofed by process/product design.

1

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Detection Column Item / Process Step Function

Potential Failure Mode

Potential Effect(s) of Failure

S e v

C l a s s

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

O c c u r

Current Process Controls Prevent Detect

D e t e c

R P N

Response & Recommended Traget Actions Complete Date

Action Results Action Taken

S E V

O C C

D E T

Detection Column

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R P N

RPN / Risk Priority Number RPN = Severity x Occurrence x Detection Top 20% of Failure Modes by RPN R P N

Failure Modes 20

Evaluation by RPN Only – Case 1 • S=5 O=5 D=2 RPN = 50

– Case 2 • S=3 O=3 D=6 RPN = 54

– Case 3 • S=2 O=10, D=10 = 200

WHICH ONE IS WORSE?

– Case 4 • S=9 O=2 D=3 = 54

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Example – Extreme Safety/Regulatory Risk • =9 & 10 Severity

– High Risk to Customer Satisfaction • Sev. > or = to 5 and Occ > or = 4

– Consider Detection only as a measure of Test Capability.

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Example of Significant/ Critical SpecialThreshold Characteristics Matrix S E V E R I T Y

10 9 8 7 6 5 4 3 2 1

POTENTIAL CRITICAL CHARACTERISTICS Safety/Regulatory POTENTIAL SIGNIFICANT CHARACTERISTICS Customer Dissatisfaction

ANOYANCE ZONE ALL OTHER CHARACTERISTICS Appropriate actions / controls already in place

1

2

3 4 5 6 7 8 9 10 OCCURRENCE

*Used by permission of Ford Motor Company

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Actions Potential Failure Mode and Effects Analysis (Design FMEA)

Your Company Name Here System Subsystem Component:

FMEA Number: Page of Prepared by: FMEA Date (Orig.):

Design Responsibility: Key Date:

Model Year/Vehicle (s):

(Rev.):

Core Team: Item Potential Failure Mode Function

Potential Effect (s) of Failure

s e v

c l a s s

Action Results Potential Cause (s)/ Mechanism (s) Failure

o c c u r

Current Design Controls

D e t e c

R. P. N.

Recommended Action(s)

Responsibility & Target Completion Date

Actions Taken

s e v

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o c c

D e t

R. P. N.

Actions EXAMPLE: Project: Issue Number 143

Date Of Meeting: Issue

Status/ Open Date

Issue Champion

Action Number

Action Date

Action

Person Resp. Team

Completion Date

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Re-rating RPN After Actions Have Occurred Potential Failure Mode and Effects Analysis (Design FMEA)

Your Company Name Here System Subsystem Component:

FMEA Number: Page of Prepared by: FMEA Date (Orig.):

Design Responsibility: Key Date:

Model Year/Vehicle (s):

(Rev.):

Core Team: Item

Potential Failure Mode Function

Potential Effect (s) of Failure

S e v

C l a s s

Potential Cause (s)/ Mechanism (s) Failure

O c c u r

Current Design Controls

D e t e c

R. P. N.

Recommended Action(s)

Responsibility & Target Completion Date

Action Results Actions Taken

S O D R. e c e P. v c t N.

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Re-rating RPN After Actions Have Occurred – – – –

Severity typically stays the same. Occurrence is the primary item to reduce / focus on. Detection is reduced only as a last resort. Do not plan to REDUCE RPN with detection actions!!! • 100% inspection is only 80% effective! • Reducing RPN with detection does not eliminate failure mode, or reduce probability of causes • Detection of 10 is not bad if occurrence is 1

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Summary – FMEA can be used creatively in continuous processing. – Linking key customer requirements to process outputs instead of standard product grade is valuable. – Future customer requirements will drive new and modified processes to achieve specialty results as a normal practice

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The FMEA is a living document and should always reflect the latest Design level , as well as the latest relevant actions in production

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Thank you

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