Failure Mode and Effect Analysis
Lecture 5-2
Implementation Issues
References:
1. Failure Modes and Effects Analysis, Paul Paladay, PT Publications, 1995
2. “FMEA - A Curse or a Blessing?”, S.J. Jakuba, RAC Journal, Vol. 5, No. 4, 1997
3. High Quality Leadership, Erwin Rausch, John Washbush, ASQ Press, 1998
4. The Change Agents’ Handbook, David Hutton, ASQ Press, 1994
FMEA
“Good judgment
comes from
experience, and and a
lot of that comes from
bad judgment”
Will Rogers
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1
Recent Changes [2]
FMEA
In the FMEA’s Acceptance
• Historically adopted on its own merit
• New trend over the last few years enforcing the FMEA through bureaucratic
means such as supplier certification,
contract award, etc.
• Seen by some as a cure for all design
problems
• Seen by others as a curse and selfserving activity
3
Result
FMEA
• Many people “required” to do an FMEA
have little or no training
• Managerial resistance - insufficient time
allocated
• Mental resistance brought on by “do
FMEA or we but from someone else.”
• Requirement that an FMEA must be
written in an approved manner that is
unsuitable for a particular circumstance.
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2
“Cure All”
FMEA
• Leads to disappointment
• Demanding that FMEA “show” quality,
reliability, or lead time improvement in
measurable terms is unrealistic
• FMEA is Cost Avoidance, not cost
reduction
• People soon conclude that FMEA is a
waste of time and preparation is
delegated to the least qualified people
5
Potential Roadblocks
• FMEA is too subjective
• We can’t spare the people for a
review team
• We have a tight schedule,
there is no time for additional
meetings
• A complete FMEA for a
complex product could be
thousands of pages – what’s
the added value?
• Why should I worry about
potential problems, which have
not yet occurred?
FMEA
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3
Words of Caution
FMEA
Keep the reason for FMEA in perspective
• FMEA is not designed to supercede the
engineer’s work
• Every conceivable failure mode should not be
evaluated
• FMEA is not the tool for selecting the optimum
design
• FMEA, like all tools, has limitations
• It is easy to get distracted from the primary
objective of FMEA
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Words of Caution
FMEA
• The Severity, Occurrence and Detection (or
Verification) scales to be tailored to your
products and processes
• If you are not sure what number to assign to
any of the ranking scales, don’t assign the
highest number.
• The Risk Priority Number (RPN) can be
misleading (the Pareto 80-20 principle does
not apply)
• A very small RPN may require corrective
action
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4
Words of Caution
FMEA
• Because the technique examines individual
faults of system elements taken singularly,
the combined effects of coexisting failures are
not considered.
• If the system is at all complex and if the
analysis extends to the assemble level or
lower, the process can become tedious and
time consuming.
• Failure probabilities can be hard to obtain
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Words of Caution
FMEA
• FMEA will find and summarize system
vulnerability to Single Point Failures (SPF)
and may require time, effort and expense to
correct.
• Don’t ignore the role of mission planning
• Don’t develop SPF Paranoia – and demand
action for every potential SPF. You may
loose focus on system threats.
• Team members must participate, even if they
reside in another location.
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5
FMEA is a Team Activity,
BUT
FMEA
• The engineer is the subject matter
expert and usually has most of the
knowledge, and should own the FMEA
• The engineer should lead the effort
– Don’t try to do it alone
– Don’t delegate the responsibility to another
organization
The majority of the work is done
outside of the team
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Leading the FMEA
FMEA
• This takes some coordination and team
leading skills
• Individuals who may be very skilled
analytical engineers may lack these
skills
• Don’t force it on anyone
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6
2 Common Mistakes
FMEA
Oversimplifying
Overcomplicating
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Oversimplifying
FMEA
Skimping on thoroughness or
completeness is harmful in 2 ways:
1. The product or process may fail
because important considerations were
missed
2. Lowers morale - feeling of a “job well
done” is not there
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7
Overcomplicating
FMEA
Being too thorough, or covering too broad
a scope,
• Leads to FMEA’s that never get
completed and things rarely change as
a result of the analysis
• The team gets bogged down in details
and misses systems opportunities
• The team looses interest
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An Underlying Truth
FMEA
Keep this in mind,
The usefulness of FMEA depends
entirely upon what turns up. It is only
after the fact that we know the value of
the time spent dealing with potential
problems. Perhaps nothing new will be
discovered. Maybe a major problem
has been diverted. Either way, the
organization which looks ahead is the
winner
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8
FMEA Facilitator
FMEA
Coordinate the FMEA activity among
the various organizations and
disciplines.
Set target dates and monitor activity
with respect to the product development
time line.
Structure, schedule, and chair the
meetings
Insure that the FMEA documentation is consistent and
complete and available to those who need to know.
Monitor level of complexity to insure adequate detail
Provide progress reports as needed to insure management
support
Communicate with other facilitators
Training
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FMEA
Key points of training:
• Include method and terminology
• Train people who have an immediate
application
• Establish clear ground rules
– Intent is not to “throw rocks” at the design
– Intent is not to create an action list – a
good FMEA has no outstanding actions at
the end
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9
Insufficient Time
FMEA
• Difficult to prepare the first few times
– Gets easier
• May require more time in the design
and development stage
– Time spent doing FMEA well is saved
many fold in not having problems after the
product and process are finalized
• Too much administrative burden
– Engineers should not be burdened with
organizing meetings, logistics, typing
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Conducting Effective Meetings[3] FMEA
Rausch’s Laws of Meetings
• More meetings are held than are
needed
• Most meetings take longer than
necessary to bring the desired result
• More people are asked to attend most
meetings than are needed
• Few meetings are adequately prepared
Edwin Rausch
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10
Conducting Effective Meetings[3] FMEA
• If something can be addressed without a
meeting, don’t call a meeting, but handle it
other ways – phone, network, memos, etc.
• When you call a meeting, prepare carefully
• Call the minimum number of people needed
for the technical and acceptance
requirements.
• State the objective of the meeting
beforehand. Keep the meeting focused on
that outcome. Stick to the FMEA
methodology
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Conducting Effective Meetings[3] FMEA
• Make sure that there is a clear plan for
proceeding at the conclusion of the
meeting.
• Make sure that expectations are clearly
understood
• Communicate the results of the meeting
to the appropriate audience.
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11
Solutions [2]
FMEA
• Develop internal procedures
FMEA
Handbook
1
2
3
4
5
6
7
Introduction
Step-by-step Procedure
Rating Scales
Examples
Glossary of Terms
References
Forms
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Approach[1]
FMEA
• Introductory Meeting
–
–
–
–
Overview of the project - by the team leader
Brief overview of the FMEA process
Provide copies of company FMEA Handbook
Review each persons’ roles and responsibilities
• Complete FMEA Prerequisites
– Summary of design requirements, specs, reliability
requirements, customer requirements mailed to each
team member
– Engineer (and facilitator if needed) fills out as much of
the FMEA worksheet as possible - functions, potential
failure modes - and mails it to the team.
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12
Approach
FMEA
Review Meetings
• Team members fill out the rest of the FMEA
worksheet
• Team meets for 1 - 1-1/2 hrs (max) to complete work
on the FMEA. This may take 2 - 3 meetings
• After each meeting, the updated FMEA is distributed
to the team
Remember, FMEA is an iterative process and it is
constantly changing and undergoing updates.
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Score the FMEA
FMEA
FMEA WORKSHEET
PRODUCT:
TYPE: DESIGN PROCESS OTHER___________________ ITEM:
FUNCTION
O
C
C
U
R
R
A
N
C
E
10
9
8
7
6
5
4
3
2
1
0
1b
4b 2c
POTENTIAL EFFECTS OF
FAILURE MODE FAILURE
S
3b
O
1
a
b
7
4
3
9
2
a
b
c
2
7
5
3
6
8
3
a
b
c
d
8
6
3
3
2
4
3
4
4
a
b
4
4
2
8
2b
3d
2a 3c
POTENTIAL
CAUSES
1a
4a
3a
0 1 2 3 4 5 6 7 8 9 10
SEVERITY
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Leverage Causes
FMEA
• A common problem shared by all
organizations is the allocation of a fixed
amount of resources to an unlimited
number of opportunities
Causes
Failure Mode / Effect
1a 1b 2b 2c 3a 3b 4b
CRITICAL
ITEMS
Cause A
Cause B
Cause C
Improvement Strategy
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FMEA
First - try to eliminate the failure mode
Second - Minimize the severity of the
failure
Third - Reduce the occurrence of the
failure mode
Fourth - Improve the detection
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