Fmea process la

Potential Failure Mode &
Effects Analysis FMEA
PROCESS FMEA

ISO TS 16949:2002 Auditor Course Supplement

Robere & Associates (Thailand) Ltd. 1

Course Objectives
• By the end of the course the
participant should be able to;
– Understand how to audit FMEA’s
process
• identify the two types of FMEA’s
• complete a Process FMEA for a project
• understand how to determine the RPN
and its implication

Robere & Associates (Thailand) Ltd.
2

Failure Mode and Effects Analysis

• ISO TS requires FMEA’s to be generated and
revised during the following stages;
– Advanced Product Quality Planning - before or at
design concept finalisation/prior to tooling for
production
– Design reviews
– As a result of customer complaints
– As as result of customer/field returns
• FMEA’s are LIVING DOCUMENTS

3


• What is an FMEA?
– An FMEA is a structured process used to
analyse design and/or process activities and
to assure that potential failure modes have
been addressed and effects analysed.

4


• An FMEA is a
team process not a
single person
process

5


• Benefits of FMEA’s

– 1. Utilises previous history and
associated failure modes to
assist in developing quality
products during design - better
understanding of the product

6



– 2. An objective evaluation of the
design or process - not subjective.
It forces an organisation to
quantify

7



– 3. Cost & time savings - The
process identifies potential
causes/mechanisms of failure
before they occur

8



– 4. Provides a system for
establishing design and
process improvements and
for identifying Special
Characteristics

9



• 5. A structured proactive system that
aims to provide for Customer
Satisfaction

10


• There are two types of FMEA’s

• 1. Design FMEA
– Cooling system for vehicle, spoiler assembly,
wiring harness etc..
• 2. Process FMEA
– Injection moulding, welding, assembling etc...

11


• Definition of a Design FMEA
– A design FMEA is a structured process
used by Design Responsible companies to
ensure, to the extent possible, that possible
failure modes and their associated causes
and mechanisms have been considered
during the design process.

12

• Examples of when Design FMEA’s may be used;
– A company may be responsible for the complete
design of the cooling system of a vehicle.
– A company may be responsible for designing a
complete trimmed seat assembly
– A company may be responsible for developing and
designing a material to reduce Noise and Vibration in a
vehicle

13


• Definition of a Process FMEA
– A process FMEA is a structured process
used by a manufacturing company to
identify potential failure modes and their
associated causes and mechanisms for the
manufacture and assembly of product.

14


• Examples of when Process FMEA’s
may be used;
– A company has been provided with all of
the technical information to manufacture;
• An injection moulded interior door handle
• A metal pressed bracket
• A family of fasteners

15

How to Complete a
Process FMEA

Robere & Associates (Thailand) Ltd. 16

Process Failure Mode and Effects
Analysis

• How to complete a Process FMEA
1. FMEA number
• A number used for tracking and identifying the
Process FMEA

– GM -001A

17

Analysis

– How to complete a Process FMEA
2. Item
• Enter the name and number of the system, sub-system
or component for which the process is being analysed

– Rear Decklid Spoiler 92078645

18

Analysis
3. Process Responsibility
• Indicate the OEM, department and/or group
which is responsible for the Process

– Spoiler Design Team

19

Analysis
4. Prepared by:
• Enter the contact details of the person
responsible for preparing the Process FMEA.
This is typically the Process/Product Engineer

– Max Smart

20

Analysis
5. Model Year(s)/Vehicle(s)
• Enter the intended model year(s) and vehicle
lines that will utilise and/or be affected by the
Process being analysed, if known

– WH 1999

21

Analysis
6. Key Date
• The key date is defined as the due date for the
Process FMEA. This date should not exceed
the scheduled start of production.

– July 1999

22

Analysis
7. FMEA Date
• This date is defined as the original date the
Process FMEA was compiled and the latest
revision date.

– June 5, 1998, August 10, 1999 Rev 8

23

Analysis
8. Core Team
• List the names of the responsible individuals
and departments who have participated in the
generation of the Process FMEA.

– AW, PS, JA, RK, MH

24

Analysis
9. Process/Function Requirements
• Enter the name of the process being analysed.
It is important to be as concise as possible. Use
the same terminology as per any reference
documents.
• Examples are;
trimming, vacuum forming, welding etc..

25

Analysis
10. Potential Failure Mode
• Enter the potential failure mode(s) for that
process. Examples of failure modes might be,
but are not limited to;
– Stressing, Burrs, Cracking, Burning, Flash,
Fails to open, Part leaking, bent, brittle,
worn, tool mark etc...

26

Analysis
11. Potential Effects of Failure
• What if the failure occurs, what are the potential
effects? These need to be written from the customers
perspective. This can mean the next operation or
machine, not just end customer.
• Examples
• inoperable, unsatisfactory appearance, noisy because
of vibration, uncomfortable, erratic operation, unable
to fit or locate etc...

27

Analysis
12. Severity
• Enter the severity rating as described in
Appendix 1. The severity is an assessment of
the seriousness of the problem

28

Analysis
13. Classification
• Enter the special characteristic symbol as per
customer requirements for any critical,
significant, major, safety or Key characteristic.
ISO TS Section II should define the type of
symbol required.
ISO TS requires that all special characteristics
are addressed during the FMEA stage.

29

Analysis
14. Potential Cause(s)/Mechanism(s) of
Failure
• Enter any potential reasons for these failures
– Examples are:
– Improper weld
– Part not mounted correctly before drilling
– Incorrect cycle time
– Inadequate gauging
– Human error, Fatigue, interaction..
– Tool worn

30

Analysis
15. Occurrence
– Enter the Occurrence as per Appendix 2.
The Occurrence is defined is the
probability or the likelihood that the
specific cause or mechanism will occur.
This may be based on previous field
history, similar products and experience

31

Analysis
16. Current Process Controls
• Enter the current Process
verification/validation activities that will assure
the adequacy of the Process
• Typical examples may be, SPC, gauging
error proofing etc...

32

Analysis
17. Detection
• Enter the detection probability as per Appendix
3. Detection is defined as the ability of the
proposed Process controls to detect any
Process weakness or potential failure.

33

Analysis
18. Risk Priority Number (RPN)
• The Risk Priority Number is defined as the
Severity multiplied by the Occurrence
multiplied by the Detection. The RPN is a
measure of the Process risk. The RPN will be
between 1 and 1000. It is the responsibility of
the group to define what a high RPN is and
take the appropriate actions.

34

Analysis
19. Recommended Action(s)
• When high RPN’s are established corrective
action should be incorporated with a focus on
reducing the Process risk

35

Analysis
20. Responsibility
• Enter the name of the person(s) or organisation
who has the responsibility for implementing
the corrective action(s). This should also
include a target date for completion.

36

Analysis
21. Actions taken
• Enter the effectiveness and the results of the
actions taken

37

Analysis
22. Severity
• Re-enter the severity rating as described in
Appendix 1. The severity is an assessment of
the seriousness of the problem.

38

Analysis
23. Occurrence
• Re-enter the Occurrence as per Appendix 2.
The Occurrence is defined as the probability or
the likelihood that the specific cause or
mechanism of failure will occur. This may be
based on previous field history, similar
products and/or experience.

39

Analysis
24. Detection
• Re-enter the Detection probability as per
Appendix 3. Detection is defined as the ability
of the proposed Process controls to detect any
Process weakness or potential failure.

40

Analysis
25. Resulting RPN
• Based on the corrective action, calculate the
RPN and record this result. If further action is
required repeat the corrective action steps in
order to reduce the RPN.

41

Appendix 1 Severity rating for Process FMEA
Eff ect Cu st o m er Ef fect Ma nu fa ct u r ing/ Asse m bly Effect Ra nk in g

Hazardous- Very high severity ranking when a pot ential Or may endanger machine or assembly 10
without failure mode aff ects saf e vehicle operat ion operator, without warning.
warning and/or involves nonconpliance wit h
government regulat ion without warning.

Hazardous Very high severity ranking when a pot ential Or may endanger machine or assembly 9
with failure mode aff ects saf e vehicle operat ion operator, with warning
warning and/or involves nonconpliance wit h
government regulat ion without warning
Very High Vehicle/ item is inoperable, loss of primary Or 100% of product may have t o be 8
function scrapped, or vehicle/it em repaired in
repair dept wit h a repair time greater
then 1 hr
High Vehicle/ item is operable, but at a reduced Or product may have to be sorted and a 7
level of perf ormance. Customer very port ion (less than 100% ) scrapped, oer
dissatisf ied. vehicle/item repaired in the repair
department with a repair t ime between a
half hour t o one hour.
Moderate Vehicle/ item is operable, but Or a portion (less than 100% ) of the 6
comfort /convenience items inoperbale. product may have to be scrapped with no
Customer dissat isfied sort ing, or vehicle/it em repaired in repair
department with a repair t ime of less t hen
1 hour
Low Vehicle/ item is operable, but Or 100% of product may have t o be 5
comfort /convenience items operbale at a reworked, or vehicle it em repaired off line
reduced level of performance but does not fo to repair dept
Very low Fit and f inish/squeak and rattle item does Or t he product may have to be sorted, 4
not conform. Defect not iced by most with no scrap, and a portion(less then
customers (greater then 75% ) 100% ) scrapped.
Minor Fit and f inish/squeak and rattle item does Or a portion (less then 100% ) of the 3
not conform. Defect not iced by 50% product may have to be reworked with no
customers. scrap, on line but out of station.

Very Minor Fit and f inish/squeak and rattle item does Or a portion (less then 100% ) of the 2
not conform. Defect not iced product may have to be reworked with no
bydiscriminating customers (less then 25% ) scrap, on line but in stat ion.

None No discernable eff ect. Or slight inconvenience to operation or 1

42 operator, or no effect

Appendix 2
Occurrence rating for Process FMEA
Probability of failure Possible failure rates Ppk Ranking
Very High - Persistent failures ≥ 100 per thousand pieces < 0.55 10
50 per thousand pieces ≥ 0.55 9
High - Frequent failures 20 per thousand pieces ≥ 0.78 8
Moderate - Occasional Failures 5 per thousand pieces ≥ 0.94 6
Low - Isolated failures associated with 0.5 per thousand pieces ≥ 1.20 3
similar processes
Low - Relatively few failures 0.1 per thousand pieces ≥ 1.30 2

Remote - Failure is unlikely. ≤ 0.01 per thousand pieces ≥ 1.67 1

43

Detection Criteria Inspection Suggested Range of Ranking
Types Detection Methods

Almost
impossible
Absolute
certainty of non-
A B C
X Cannot detect or is not checked 10 Appendix 3
detection
Very remote Controls will
probably not
X Control is achieved with indirect
or random checks only
9 Detection
Remote
detect
Controls have
poor chance of
X Control is achieved with visual
inspection only
8 rating for
Process
detection
Very Low Controls have X Control is achieved with double 7
poor chance of visual inspection only

FMEA
detection
Low Controls may X X Control is achieved with SPC 6
detect charting methods
Moderate Controls may X Control is based on variable 5
detect gauging after parts have left the
station, or GO/NO GO gauging
performed on 100% of the parts
after the parts have left the
station Inspection types
Moderately Controls have a X X Error detection in subsequent 4
High good chance to operations, OR gauging
detect performed on setup and first A = Error proofed
piece check
B = Gauging
High Controls have a X X Error detection in station, or 3
good chance to detection in subsequent C = Manual Inspection
detect operations by multiple layers of
acceptance: supply, inspect,
install and verify. Cannot accept
discrepant part.
Very High Controls X X Error detection in-station 2
almost certain (automatic gauging with
to detect automatic stop feature). Cannot
pass discrepant part.
Very High Controls X Discrepant parts cannot be made 1
certain to because item has been error-
detect proofed by process/product

design
44

Auditing PFMEA’s
1. Is the PFMEA conducted by a cross functional
team?
2. Has the Key date been defined
3. Is it consistent with the customer’s PPAP date?
4. Does the organisation consider all of the elements
within the process flow chart?
5. Has the organisation defined what constitutes a
high RPN
6. Does the organisation follow the definition of a
high RPN

45

Auditing PFMEA’s
7. Are recommended actions completed prior to the
Key date
8. Do the sequence of dates make sense?
9. How are revisions recorded?
10. Does the organisation ensure the PFMEA is a living
document?
11. Verify the occurrence rankings are based on
objective evidence
12. Ensure the organisation is using the correct
rankings for Severity, Occurrence and Detection

46

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