FMEA Training

Failure Mode and Effects Analysis

Failure Mode and Effects Analysis

(FMEA)

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Sequence of System

Sequence of System

Drawings and Specification

Drawings and Specification

Feasibility Study

Feasibility Study

Process Flow Diagram

Process Flow Diagram

Process FMEA

Process FMEA

Control Plan

Control Plan

Process Sheet and Work

Process Sheet and Work

Instruction

What Is An FMEA?

FMEA is a systematic analytical, logical & progressive

FMEA is a systematic analytical, logical & progressive

potential failure analysis technique (a paper test) that

potential failure analysis technique (a paper test) that

combines the technology and experience of several

combines the technology and experience of several

engineering disciplines in identifying foreseeable failure

engineering disciplines in identifying foreseeable failure

modes of a product / process/ system and service and

modes of a product / process/ system and service and

planning for its elimination.

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Types of FMEA

Types of FMEA

•

System FMEA (System / Sub system / Component)

_{System FMEA (System / Sub system / Component)}

•

Design FMEA (System/Sub System / Component)

_{Design FMEA (System/Sub System / Component)}

•

Process FMEA

_{Process FMEA}

•

Service FMEA

_{Service FMEA}

•

Machines

_Machines

Detect Prevent R P N D E T O C C S E V Action Taken Action Results Response & Traget Complete Date Recommended Actions R P N D e t e c Current Process Controls O c c u r Potential Cause(s)/ Mechanism(s) Of Failure C l a s s S e v Potential Effect(s) of Failure Potential Failure Mode Item / Process Step Detect Prevent R P N D E T O C C S E V Action Taken Action Results Response & Traget Complete Date Recommended Actions R P N D e t e c Current Process Controls O c c u r Potential Cause(s)/ Mechanism(s) Of Failure C l a s s S e v Potential Effect(s) of Failure Potential Failure Mode Item / Process Step Function FMEA DATE(ORIG.) CORE TEAM PREPARED BY KEY DATE

MODEL YEAR(S) / VEHICLE(S)

OF PAGE PROCESS RESPONSIBILTY ITEM FMEA NUMBER POTENTIAL

FAILURE MODE AND EFFECT ANALYSIS (PROCESS FMEA)

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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

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

Detect Prevent R P N D E T O C C S E V Action Taken Action Results Response & Traget Complete Date Recommended Actions R P N D e t e c Current Process Controls O c c u r Potential Cause(s)/ Mechanism(s) Of Failure C l a s s S e v Potential Effect(s) of Failure Potential Failure Mode Item / Process Step Detect Prevent R P N D E T O C C S E V Action Taken Action Results Response & Traget Complete Date Recommended Actions R P N D e t e c Current Process Controls O c c u r Potential Cause(s)/ Mechanism(s) Of Failure C l a s s S e v Potential Effect(s) of Failure Potential Failure Mode Item / Process Step Function

Severity

Column

Severity Column

Severity Column

An assessment of the seriousness of the effect to

An assessment of the seriousness of the effect to

- The next level of operation

- The next level of operation

- Assembly operation

- Assembly operation

- End User ( Final Customer)

- End User ( Final Customer)

•

Applies to the effect and effect only

_{Applies to the effect and effect only}

•

Severity expressed as a number on a scale of 1 to 10

_{Severity expressed as a number on a scale of 1 to 10}

•

A reduction in severity ranking can be achieved only through a product

_{A reduction in severity ranking can be achieved only through a product}

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AUTOMOTIVE EXAMPLE SEVERITY EVALUATION CRITERIA

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

No discernible effect. None

2 Or a portion (less than 100% of the product may have to be

reworked, with no scrap, on-line but in-station. Fit & Finish/Squeak & Rattle item does not conform. Defect

noticed by discriminating customers (less than 25%) Very Minor

3 Or a portion (less than 100%) of the product may have to be

reworked, with no scrap , on-line but out of station. Fit & Finish/Squeak & Rattle item does not conform. Defect

noticed by 50% of customers Minor

4 Or the product may have to be sorted, with no scrap, and a portion

(less than 100%) reworked. Fit & Finish/Squeak & Rattle item does not conform. Defect

noticed by most customers (greater than 75%) Very Low

5 Or 100% of product may have to be reworked, or vehicle/item

repaired offline but does not got to repaire department. Vehicle/Item operable, but comfort/Convenience item(s)

inoperable at a reduced level of performance. Customer somewhat dissatisfied.

Low

6 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.

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

Moderate

7 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.

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

High

8 Or 100% of product may have to be scrapped, or vehicle/item

repaired in repair department with a repair time greater than one hour.

Vehicle/Item inoperable (loss of primary function) Very high

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

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

Hazardous with warning

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

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

Hazardous without warning R anki ng 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 ) 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)

Classification And Definition

Column

S e v R. P. N. Item Function Potential Failure Mode Potential Effect(s) of Failure C l a s s Potential Cause(s) / Mechanism(s) of Failure O c c u r Current Design Controls D e t e c Recommended Actions Response & Target Complete Date Actions Taken

Classification and

Definition Column

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

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Inadequate

Electrical

Connection

Inadequate

Electrical Connection

Motor

Stops

Causes

Cause

Failure Mode/Cause Relationship

In Different FMEA Levels

Failure

Mode

Failure

Mode

Inadequate

Locking

Feature

Harness

Too Short

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.

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Occurrence Column

Detect Prevent R P N D E T O C C S E V Action Taken Action Results Response & Traget Complete Date Recommended Actions R P N D e t e c Current Process Controls O c c u r Potential Cause(s)/ Mechanism(s) Of Failure C l a s s S e v Potential Effect(s) of Failure Potential Failure Mode Item / Process Step Detect Prevent R P N D E T O C C S E V Action Taken Action Results Response & Traget Complete Date Recommended Actions R P N D e t e c Current Process Controls O c c u r Potential Cause(s)/ Mechanism(s) Of Failure C l a s s S e v Potential Effect(s) of Failure Potential Failure Mode Item / Process Step Function

Occurrence

Column

Occurrence Evaluation Criteria

Probability of Likely Failure Rates Over Design Life Ranking

Failure

SUGGESTED OCCURRENCE EVALUATION CRITERIA

Very High: Persistent failures

High: Frequent failures

Moderate: Occasional failures

Low: Relatively few failures

≥

100 per thousand vehicles/items

50 per thousand vehicles/items

20 per thousand vehicles/items

10 per thousand vehicles/items

5 per thousand vehicles/items

2 per thousand vehicles/items

1 per thousand vehicles/items

0.5 per thousand vehicles/items

0.1 per thousand vehicles/items

≤

10

9

8

7

6

5

4

3

2

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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.

Example of Significant/ Critical

Threshold

10

9

8

7

6

5

4

3

2

1

1

2

3

4

5

6

7

8

9 10

S

E

V

E

R

I

T

Y

POTENTIAL CRITICAL

CHARACTERISTICS

Safety/Regulatory

POTENTIAL

SIGNIFICANT

CHARACTERISTICS

Customer Dissatisfaction

ALL OTHER CHARACTERISTICS

Appropriate actions /

controls already in place

Special Characteristics Matrix

ANOYANCE

ZONE

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Detection Rating

1 Discrepant parts cannot be made because item has been

error-proofed by process/product design. X

Controls certain to detect. Very High

2 Error detection in-station (automatic gauging with automatic

stop feature). Cannot pass discrepant part.. X

X Controls almost certain to detect.

Very High

3 Error detection in-station, or error detection in subsequent

operations by multiple layers of acceptance: supply, select, install, verify. Cannot accept discrepant part. X

X Controls have a good chance to detect

High

4 Error detection in subsequent operations, OR gauging

performed on setup and first piece check (for set-up causes only.)

X X Controls have a good chance to detect

Moderately High

5 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.

X Controls may detect

Moderate

6 Control is achieved with charting methods, such as SPC

(Statistical Process Control.) X

X Controls may detect

Low

7 Control is achieved with double visual inspection only

X Controls have poor chance of detection.

Very Low

8 Control is achieved with Visual Inspection only.

X Controls have poor chance of detection.

Remote

9 Control is achieved with indirect and random checks only.

X Controls will probably not detect

Very Remote

10 Cannot detect or is not checked.

X Absolute certainly of non- detection

Almost Impossible

C B A

Ranking Suggested Range of Detection Methods

Inspection Types Criteria

Detection Column

Detect Prevent R P N D E T O C C S E V Action Taken Action Results Response & Traget Complete Date Recommended Actions R P N D e t e c Current Process Controls O c c u r Potential Cause(s)/ Mechanism(s) Of Failure C l a s s S e v Potential Effect(s) of Failure Potential Failure Mode Item / Process Step Detect Prevent R P N D E T O C C S E V Action Taken Action Results Response & Traget Complete Date Recommended Actions R P N D e t e c Current Process Controls O c c u r Potential Cause(s)/ Mechanism(s) Of Failure C l a s s S e v Potential Effect(s) of Failure Potential Failure Mode Item / Process Step Function

Detection

Column

20

RPN / Risk Priority Number

Top 20% of Failure

Modes by RPN

R

P

N

Failure Modes

RPN = Severity x Occurrence x Detection

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

– Case 4

• S=9 O=2 D=3 = 54

WHICH ONE IS

WORSE?

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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.

Example of Significant/ Critical

Threshold

10

9

8

7

6

5

4

3

2

1

1

2

3

4

5

6

7

8

9 10

S

E

V

E

R

I

T

Y

POTENTIAL CRITICAL

CHARACTERISTICS

Safety/Regulatory

POTENTIAL

SIGNIFICANT

CHARACTERISTICS

Customer Dissatisfaction

ALL OTHER CHARACTERISTICS

Appropriate actions /

controls already in place

Special Characteristics Matrix

ANOYANCE

ZONE

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Actions

Item Function System Subsystem Component: Model Year/Vehicle (s): Core Team:

Your Company Name Here Potential

Failure Mode and Effects Analysis (Design FMEA) Design Responsibility: Key Date: FMEA Number: Page of Prepared by:

FMEA Date (Orig.): (Rev.):

Potential Failure Mode 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 Actions Taken s e v o c c D e t R. P. N. A c t i o n R e s u l t s

Actions

EXAMPLE:

Project: Date Of Meeting: Issue Number Issue Status/ Open Date Issue Champion Action Number Action Date

Action Person Resp. Team

Completion Date 143

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Re-rating RPN After Actions Have Occurred

Item Function System Subsystem Component: Model Year/Vehicle (s): Core Team:

Your Company Name Here Potential

Failure Mode and Effects Analysis (Design FMEA) Design Responsibility: Key Date: FMEA Number: Page of Prepared by:

FMEA Date (Orig.): (Rev.):

Potential Failure Mode 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 Actions Taken S e v O c c D e t R. P. N. A c t i o n R e s u l t s

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

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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

The FMEA is a living document

The FMEA is a living document

and should always reflect the latest

and should always reflect the latest

Design level , as well as the latest

Design level , as well as the latest

relevant actions in production

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Thank you