POTENTIAL FAILURE MODE AND EFFECTS ANALYSIS

Guidelines for Preparing Process FMEA

1 FMEA Number:

2 Part No & Part Name

3 Rev

4 Operation

5 Prepared By:

6 FMEA Date:

7 Core Team:

8 Process No.

9 Description

Process Function &

10
Requirements

Potential failure
11
mode

Potential Effects of
12
failure

13 Severity (S)

14 Classification

Potential causes of
15
failure

Current process
16
controls Prevention:

17 Occurrence(O)

Current process
18
controls Detection:
19 Detection(D)

Risk Priority Number

20
(RPN)

Recommended
21
Action:

Responsibility for the

22 Recommended
Action(s)

23 Action(s) Taken:

24 Action Results:
POTENTIAL FAILURE MODE AND EFFECTS ANALYSIS

Guidelines for Preparing Process FMEA

Enter the FMEA document number, which may be used for tracking.

Enter the Item number and name for which FMEA is prepared

Enter the issue (revision level) of item

Enter the operation name if FMEA is done for particular operation

Enter the name, telephone number, and company of the engineer responsible for
preparing the FMEA.

Enter the date the original FMEA was compiled and the latest revision date.

List the names of the responsible individuals and department that have the
authority to identify and /or perform tasks. (It is recommended that each team
member’s name, department, telephone number, address, etc be included on a
distribution list.)

Enter the Operation No. corresponding to Process Flow / Control Plan

Enter a simple description of the process or operation being analyzed. (eg.,

turning, drilling, tapping, welding, assembling)
Enter the requirements of the particular Part characters (eg.,No Missing of
Operation , Thread length as per Spec. OD with Tol..etc.)
Potential failure mode is defined as the manner in which the process could
potentially fail to meet the process requirements and or design intent as
described in the process function requirements column.
Potential effects of failure are defined as the effects of the failure mode on the
customers. Describe the effects of failure in terms of what the customer might
notice or experience, remembering that the customer may be an internal
customer as well as the ultimate end user.
Severity is the rank associated with the most serious effect for a given failure
mode. Refer table.
This column may be used to classify any special product or process
characteristics. (e.g. critical, key, major, significant) for components ,
subsystems, or systems that may require additional process controls.
Potential cause of failure is defined as how the failure could occur, described in
terms of something that can be corrected or can be controlled.
Current Process Controls are descriptions of the controls that either prevent to the
extent possible the failure mode or cause/mechanism of failure from occurring or
detect the failure mode or cause/mechanism of failure should it occur. These
controls can be process controls such as error/mistake proofing, statistical process
control (SPC)
Occurrence is likelihood that a specific cause / mechanism failure will occur. Refer
table
Detect the cause/mechanism of failure or the failure mode, and lead to corrective
action(s). The evaluation may occur at the subject operation or at subsequent
operations.
Detection is the rank associated with the best detection control listed in the
process control column. Refer table
The risk priority number is the multiplication of severity (S) occurrence (O)
detection (D) rankings.
ie.(S)(O)(D) . Eg. If Sev-9 , Occ-5 & Det-8 then RPN should be 9X5X8= 360
Engineering assessment for preventive/corrective action should be that directed
at high severity, high RPN and other items designated by the team.The intent of
any recommended action is to reduce rankings in the following order :severity,
occurrence,and detection.

Enter the individual responsible for the recommended action, and the target
completion date.

After the action has been implemented, enter a brief description of the actual
action and effective date.

After the preventive/corrective action has been identified, estimate and record the
resulting severity, occurrence, and detection rankings. Calculate and record the
resulting RPN.If no actions are taken, leave the related ranking columns blank.All
revised ratings are reviewed and if further action is considered necessary, repeat
the analysis. The focus should always be on continuous improvement.
 Process Failure Mode & Effects Analysis ( Process FMEA )
Part Number Part Name FMEA Number:

Operation Rev. Prepared By:

Core Team FMEA Date (Orig.)

FMEA Date (Rev.)

Process Recommended Responsibility & Target Completion Dates Action Results

Actions

OCCURRENCE

DETECTION
SEVERITY
Potential Potential Causes(s) /
Function / Potential Failure Current Process Current Process

RPN
Effect(s) of Class. Mechanism (s) of Action Taken
Requirements Mode Failure Failure Controls Prevention Controls Detection
Cause Prevention /
Detection &

OCC
DET
SEV
No. Description Who ? Where ? When ? How ?
Failure Mode
Detection

o n
iti
Ed
IV
Action Results
RPN
 SUGGESTED PFMEA Severity Evaluation Criteria

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

Potential Failure mode affects safe

vehicle
operation and / or involves
Failure to noncompliance Failure to
meet with government regulation without meet
safety and warning safety and
/ or / or
Regulatory Potential failure mode affects safe Regulatory
Requireme vehicle 9 Requireme
nts operation and / or involves nts
noncompliance
with government regulation with
warning.

Loss of Primary function (vehicle

Major
inoperable, does not affect safe vehicle
Disruption
operation)
Loss or
Degradatio
n of
Primary Degradation of primary function
Function (vehicle operable, but at reduced level Significant
of Disruption
performance)

Loss of Secondary function (vehicle

Loss or operable, but comfort / convenience
Degradatio functions inoperable)
Moderate
n of Degradation of secondary function Disruption
Secondary (vehicle operable, but comfort /
Function convenience functions at reduced level
of performance)

Appearance or Audible Noise, Vehicle

operable, item does not conform and
noticed by most customers (>75%)
Moderate
Disruption
Appearance or Audible Noise, vehicle
Annoyance operable, item does not conform and
noticed by many customers (50%)

Appearance or Audible Noise, vehicle

operable, item does not conform and Minor
noticed by discriminating customers Disruption
(<25%)
No effect No discernible effect No effect
D PFMEA Severity Evaluation Criteria

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

May endanger operator

(machine or assembly) 10
without warning.

May endanger operator

(machine or assembly) with 9
warning

100% of product may have

to be scrapped. Line 8
shutdown or stop ship.

A portion of the production

run may have to be scrapped.
Deviation from
7
primary process including
decreased line speed or
added manpower.
100% of production run may have
to be reworked off line and 6
accepted.
A portion of the production
run may have to be
5
reworked off-line &
accepted.

100% of production run may have

to be reworked in station before it is 4
processed.

A portion of the production

run may have to be
3
reworked in-station before it is
processed.

Slight inconvenience to
process, operation, or 2
operator

No discernible effect 1
 Suggested PFMEA Occurrence Evaluation Criteria
Likelihood Criteria : Occurrence of cause – PFMEA
of Failure ( Incidents per item / vehicle )
100 per thousand
Very High
1 in 10
50 per thousand
1 in 20
20 per thousand
High
1 in 50
10 per thousand
1 in 100
2 per thousand
1 in 500
0.5 per thousand
Moderate
1 in 2,000
0.1 per thousand
1 in 10,000
0.01 per thousand
1 in 1,00,000
Low
0.001 per thousand
1 in 10,00,000
Failure is eliminated through preventive
Very Low
control
Evaluation Criteria

Ranking

10

1
 SUGGESTED PFMEA Detection Evaluation Criteria
Opportunity for Criteria : Likelihood of Detection by
Detection Process Control
No detection
No current process control; Cannot detect or is not analyzed.
opportunity
Not likely to detect Failure Mode and / or Error (Cause) is not easily detected (e.g.,
at any stage random audits)
Problem Detection Failure Mode detection post – processing by operator through
Post Processing visual / tactile / audible means
Failure Mode detection in-station by operator through visual /
Problem Detection tactile / audible means or post-processing through use of attribute
at Source gauging (go / no go, manual torque
check / clicker wrench, etc.)

Failure Mode detection post-processing by operator through use of

Problem Detection
variable gauging or in-station by operator through use of attribute
Post Processing
gauging (go / no-go, manual torque check / clicker wrench, etc.)

Failure Mode or Error (Cause) detection in-station by operator

through use of variable gauging or by automated controls in-station
Problem Detection that will detect discrepant part and notify operator (light, buzzer
at Source etc.).
Gauging performed on setup and first-piece check (for set-up causes
only)
Failure Mode detection post-processing by automated controls that
Problem Detection
will detect
Post Processing
discrepant part and lock part to prevent further processing.
Failure Mode detection in-station by
Problem Detection automated controls that will detect
at Source discrepant part and automatically lock part in station to prevent
further processing.
Error Detection
Error (Cause) detection in-station by automated controls that will
and / or Problem
detect error and prevent discrepant part from being made.
Prevention
Error (Cause) prevention as a result of
Detection not
fixture design, machine design or part
applicable; Error
design. Discrepant parts cannot be made because item has been
Prevention
error-proofed by process / product design.
on Criteria
Likelihood
Rank
of Detection
Almost
10
Impossible

9 Very Remote

8 Remote

7 Very Low

6 Low

5 Moderate

4 Moderately High

3 High

2 Very High

1 Almost Certain
 FMEA LISTS
SEVERITY SCALE
10 Hazardous - w/o warning
9 Hazardous - w/ warning
8 100% Product Scrap Line Shutdown or Stop Ship
7 A Portion of the Production may have to be Scrapped
6 100% of Production run may have to be Reworked Offline and Accepted
5 100%
4 A Portion of the Production
of production run may run may
have tohave to be Reworked
be reworked in stationOffline
beforeand
it isAccepted
processed.
run may have to be
reworkedoperation,
process, in-station or
before it is processed.
operator
1 No discernible effect
OCCURENCE SCALE
10 >=100 per thousand pieces
9 50 per thousand pieces
8 20 per thousand pieces
7 10 per thousand pieces
6 2 per thousand pieces
5 0.5 per thousand pieces
4 0.1 per thousand pieces
3 0.01 per thousand pieces
2 0.001 per thousand pieces
1 Failure is Eliminated Through Preventive Control
DETECTION SCALE
10 Almost Impossible
9 Very Remote
8 Remote
7 Very Low
6 Low
5 Moderate
4 Moderately High
3 High
2 Very High
1 Almost Certain