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FMEA
FMEA – How to Plan and Organize
N
November
b 14
14, 2006
Minnesota ASQ
Jim McLinn CRE, Fellow ASQ
Slide 1
FMEA
N k d FMEA
Naked
FMEAs

What is it?
Wh d
Why
do an FMEA?

What is it good for?

How to do an FMEA

When to do an FMEA
Slide 2
FMEA
History

1960s – NASA began a version
1974 US Military and Mil Std 1629
1978 – FDA issued Hazard Analysis
1988 - Ford issued a new document for
suppliers
1990 – Chemical and Gas industry
1994 – ISO recommended Design and
P
Process
FMEAs
FMEA
1996 – FDA issued recommendation on
FMEA
FMEAs
Slide 3
FMEA
Source of Documents

Mil Std 1629
IEC 812
ARP 5580
RADC TR83-72
AIAG & SAE J1739
VDI – Z138 (German)
(
)
British Standards
Other forms exist
Slide 4
FMEA
Th FMEA Agenda
The
A
d
FMEAs can be done for a product design
or a wide variety of business processes.
processes
The intent is to improve the design or
process by finding potential problems and
avoiding them.
Slide 5
FMEA

Key FMEA Terms
Failure Mode
The manner in which a part or assembly could potentially fail to meet it’s
requirements or fail to function. It is what you may reject the part for.

Effects
The potential non-conformance stated in the terms of the next assembly or at the
system
y
((top
p level)) performance
p
(usually
(
y from the customer’s perspective).
p p
)

Causes
The potential reason(s) behind a failure mode, usually stated as an indication of a
specific
p
design
g or process
p
weakness. This starts the chain of events leadingg to
the Effect.

Analysis
By using an FMEA model
model, you will anticipate failure modes,determine
modes determine and
assess risk to the customer, product or process, and then act to neutralize the
risk or reduce it to acceptable levels

RPN
Risk Priority Number which helps prioritize the findings of the FMEA
Slide 6
FMEA
Benefits of Using FMEAs
Improves time to get reliable products to
market
Can reduce or prevent recalls (Sony
recalled 9.6
9 6 million batteries in 2006)
Identifies downstream maintenance
considerations early
May aid in complaint investigation and
meaningful corrective actions of a process
Many others exist
Slide 7
FMEA
Team Formation Challenges
1.
Team Formation

All people must participate with no dominant stars
Should be small: 5 - 8 People are best
Multi-Disciplined
Multi
Disciplined should be present
Product/Process Knowledge is key
Responsibility Level - Must have the authority to
gget things
g done
Customer Oriented – Driven to prevent problems
for customers
See Sept 2006 Quality Progress – but watch
for errors in article
Slide 8
FMEA
Additional Considerations
2 Organization of a Team
2.

Team Sponsor ( need not be present)
Team Leader (must be present and move team along)
Support Groups
Design Engineering
• Electrical,, Software or Mechanical ppeople
p
• Manufacturing or Operations
• Test Engineering
• Reliabilityy Engineering
g
g
• Field Service or repair
Scribe
C h or facilitator
Coach
f ili
Slide 9
FMEA
Design vs. Process FMEAs
Design FMEA
Engineer
g
designs
g to fulfill customer requirements
q
Failure Mode = Failure to function
Cause
= Design weakness
Detection
= Really verification and Validation (catch
design weakness before release to
manufacturing)
Process FMEA
Engineering
g
g design
g pprocess to meet specification
p
Failure Mode = Reject (Out of specification)
Cause
= Process weakness
Detection
= Controls in place on process to prevent
rejects from reaching the customer.
Slide 10
FMEA
When to do Design & Process FMEAs
Project Phases…
Phase 1:
Phase 2:
Phase 3:
Phase 4:
Phase 5:
Concept
Development
Product
Planning
Design &
Development
Test &
Validation
Release
& Ramp
Initial Design Complete
Design
g FMEA
Process FMEA
Apply learning from previous projects
Slide 11
FMEA
Some Related Tools
Function A
Function B
Function C
Functional Block Diagrams
Fault Tree Analysis
Flow Diagrams
Process Mapping
Many other tools exist

Slide 12
FMEA
Functional Block Diagrams
Is
a tool to describe the operation of
a piece
i
off equipment
i
t or process.
Allows
all team members to develop a
g of the operation
p
or
shared understanding
process to be improved.
Develops a concise starting point and
ending point for analysis of the system.
Slide 13
FMEA
FBD Example: Smoke Detector
Smoke Chamber circuit - ionizes smoke which
cases increase in voltage corresponding to signal to
be sent to control box
Vents – to smoke
chamber circuit
Indicator light - shines
when battery test button is
depressed or when alarm is
activated
+
Wire - for
sending signal to
control box
Battery - supplies voltage
to entire system
Test Button –
Activates horn
Control Box - controls
voltage to siren system
units
Siren - receives voltage and
in turn produces sound.
Control wire - sends
voltage wire to siren
Horn
How the Smoke Detector works: Smoke enters the vent and goes into the smoke chamber 2) The
chamber detects the presence of certain traces of smoke 3) If enough smoke is present chamber sends
signal to control box 4) control box then draws most of voltage in entire system to siren 5)Voltage from
battery in turn activates obnoxious siren sound
Slide 14
FMEA
FBD Example: Smoke Detector
Inputs
Process
Presence of smoke
Smoke enters assembly
Smoke enters chamber
Outputs
Successful capture
Light is activated
Smoke passes detector
Ion chamber generates
voltage
Voltage goes to control
box
Control box sends
voltage to Noise Maker
Alarm Sounds
Loud Noise
Slide 15
FMEA

What ?

Fault Tree
A logical connection diagram that shows a series of related
events which lead to potential root cause(s) of a failure.
When ?
As part of a design review
When developing a new process
To analyze
y a failure

Why?
To minimize high risk or weak links in a design
To reduce/eliminate process weaknesses
To understand root cause(s) of a failure in a multiple
connection
co
ect o oor interaction
te act o environment.
e v o e t.

Slide 16
FMEA
Smoke Detector Fault Tree
Smoke Detector
Fails to Detect
Smoke
Paint
Partial Block Diagram
Smoke does
not enter the
assembly
Smoke does
not enter
chamber
Smoke not
detected in
chamber
Vent is
blocked
Dust
Detector
broken
Dust
Insects
Incorrect
installation
Mechanical
shock
Electrical
overstress
Temperature
extreme
Dead or low
battery
Slide 17
FMEA
FMEAs - Failure Modes & Effects Analysis
What ? - Answered
When ? – Answered
Why
Wh - Answered
A
d
Time for a short example !!
Slide 18
FMEA
FMEAs - Failure Modes & Effects Analysis
Sample DFMEA Form
Slide 19
FMEA
FMEA Fault Tree to Failure Modes & Cause(s)
Smoke does
not enter the
assembly
Multiple
Level Option
Ties to FTA
Levels
Paint

Vent is
blocked
Dust
Insects
Incorrect
installation
Each of the lowest level entries in the Fault Tree are
potential Causes for the Failure Modes
p
There
should be at least one Cause for each Failure Mode branch
Slide 20
FMEA

FMEA Effects and Fault Detection
Next we complete the Effects and Fault Detection
columns together.
Slide 21
FMEA
FMEA Severity
Next
complete the Severity column
column.
Severity may ranked from 1 to 10 or as a 1 to
5 for simple
i
systems (Big
(
number
b most severe).
)
OR
1- Failure Mode is of such a minor nature that special equipment or
knowledge is required to identify. This is NO IMPACT to System.
2 - Failure Mode will result in a slight system impact and / or a slight
deterioration of system performance
performance.
3 - Failure Mode will result in noticeable system deterioration and may be
described as a “limp along”.
4 - Failure
Fail re Mode will
ill result
res lt in a non-function
non f nction of a critical ssystem
stem item
item.
5 - Failure Mode will result in a safety problem or non-compliance with
government regulation.

Slide 22
FMEA
FMEA Detection or Verification
Detectability
can be ranked from 1 to 10 or 1
to 5(Big number is least likely to be identified in
Product Development)
Development).
OR
1 - Very high probability that the Failure Mode will be identified. Verification
or Validation (V&V) or other activity will almost certainly identify the
existence of the (potential) defect.
2 - High probability that the Failure Mode will be identified. V&V or other
activities have a good chance of identifying the existence of the defect.
3 - Moderate probability that the Failure Mode will be identified. V&V or
other activities are moderately likely to identify the existence of the defect.
4 - Low probability that the Failure Mode will be identified. V&V or other
activities are not likely to identify the defect.
5 - Very
y low p
probability
y that the Failure Mode will be identified. V&V or
other activities will not or cannot identify the existence of a defect.

Slide 23
FMEA
FMEA Occurrence
Occurrence
may be ranked from 1 to 10 or 1
to 5 – as always big numbers are bad
Ranking:
1
2
3
4
5
6
7
8
9
10
more then 10 Years between fails
5 to 10 years OR
2 to 5 years
1 - Less then 0.1%
1 to 2 years
2 - 0.1% to 1%
½ to 1year
3 – 1% to 10%
Quarterly
4 – 10% to 50%
Monthly
y
5 – More then 50%
Weekly
Daily
Every few hours
The Scale Factor may be
changed as long as it is
applied consistently
consistently, ee.g.,
g one
minute might be a 10 and
twenty four hours might be
a 1.
1
Rule of Thumb: A 1 should
be at least the expected
p
life
of the product.
Slide 24
FMEA

FMEA Risk Priority Number
Calculate the Risk Priority and find top 20%

RPN is the product of S*D*O.

Top 20% are big impact items to improve

Also include all safety items to prevent or mitigate

Look at any remaining top Severity items
Slide 25
FMEA
FMEA Recommended Actions
Fill
out the Recommended Actions based on:
Safety
RPN
Issue = Yes
ranking (start with the top 20%)
When
should we do more than 20%?

Easy fixes that require minimal resources

Others that the team feels are important
Slide 26
FMEA
FMEA Who & When
Slide 27
FMEA
FMEA Audit
Key to closing out actions and making something happen
Slide 28
FMEA
FMEA Suggestions
Take advantage of existing data
Use field experience and talk to service or
repair people
Facilitate proper brainstorming – Learn how!
Avoid jumping to solutions – A Common
Engineering
i
i Mistake
i
Don’t get bogged down in arguments
A Recommended Action might be another
FMEA or a study

Slide 29
FMEA
Keepp Metrics of the FMEA – For
Example look at Statistics:
• Total number of entries
• Total number of Safety items
• Make a RPN Histogram
• Identify Entries requiring work
• Do man-load time estimates of
meetings
g
•Create a “Parking lot” if necessary
Slide 30
FMEA
Congratulations,
you have covered
th FMEA portion;
the
ti
now it is time to
address the
MANAGEMENT of
the FMEA
Slide 31
FMEA
Ways to Improve FMEAs
•Make sure there is management buy-in
•Spend
p
lots of time with ggroup
p in FMEA
•Plan, Plan, Plan
•Come
Come with forms filled out
•Identify purpose, limits, goals and customers.
•Define
D fi all
ll terms
t
up front.
f t
•Set aside enough time.
•Do the follow up
Slide 32
FMEA
Train the Team

Be sure to include training time for team
Have drawings and aides at hand.
R tteam meetings
Run
ti
for
f 2 to
t 3 hours
h
and
d
then stop.
Come prepared to all meetings
Let the team work the issues
Slide 33
FMEA
Watch Your Words

Use a complete sentence to express a complete idea.
Need a complete thought, so no stand alone words in a
section
Avoid vague words such as:

Bad, Poor & Wrong
g
Too, Low & No
Broken, Dead & Failed
Insufficient unacceptable or similar words
Insufficient,
Slide 34
FMEA
Don’t g
get Confused:
Write out whole progression if
necessary
Root Cause
Mechanism
D f t
Defect
Growth
Failure
Failure Mode
Next level impact
p
Top level Effects
Slide 35
FMEA
Other types of FMEAs

Process FMEAs are common
Maintenance or service FMEAs are done
F
Focus
on single
i l item
it
such
h as Hazards
H
d
FMEA covering something new
Functional level FMEAs
Tryy each one,, but remember theyy might
g have different
formats or requirements.
Slide 36
FMEA
Get the relationships Correct

Severity is the numerical equivalent of Effects
Occurrence speaks to likelihood of Cause
V ifi ti talks
Verification
t lk about
b t adequacy
d
off V&V ttests.
t
For a process FMEA, Detection talks about adequacy
of Current Controls.
NEVER, NEVER, NEVER depend upon the customer
to find or detect problems.
Slide 37
FMEA
Team Dynamics

Use the 30, 60 , 5 Rule
Don’t allow arguments or hidden agendas
Encourage discussion for a short time and
then either:

Come to a conclusion
Create an action to get information
U th
Use
the parking
ki lot
l t
Slide 38
FMEA
FMEA Myths

It takes a lot of time
Just a pile of paperwork in the end
C
Corrective
ti actions
ti
costt too
t much
h
Difficult to implement FMEAs because of
roadblocks
Design Engineers job, not others
No body really cares anyway
Not cost effective
Still can’t prevent safety problems
Slide 39
FMEA
I C
In
Conclusion
l i

Come Prepared
Keep it simple
Keep it focused
Keep it short
Keep it moving
Follow up
p on action items
Practice your team leader skills
Collect Lessons Learned
Slide 40