Transcript The Effective Application of FMEA

Advanced Powertrain Control
Symposium 9th July 2013
Välkommen, welcome, huān yíng, welkom, Bienvenue, willkommen,
fogadtatás, benvenuto, velkommen, powitanie, bem-vindo, croeso, bienvenido, vítejte
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The Effective Application of
FMEA
• Who am I?
• What is FMEA?
• Why do FMEA?
• Application of FMEA
• A Structured Approach
• Effective FMEA
• Use Software for FMEA
• Use an FMEA Facilitator
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What is FMEA?
Contrary to popular belief FMEA is actually an acronym for a risk analysis
called Failure Modes & Effects Analysis, and not ‘Five Men Endlessly Arguing’.
“Failure Modes & Effects Analysis is an activity that brings minds
together in a collaborative and pre-emptive way in order to avoid
failure of a system!”
FMEA is a systematic procedure that focuses on a system(s) in order to
uncover weaknesses, i.e. what can go wrong, what could possibly cause it
and what are the potential effects. FMEA then focuses on these weaknesses
with the objective of making them obsolete, or by reducing the likelihood of
failure (or risk of failure) though the implementation of corrective methods,
which in turn optimises the system.
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What is FMEA?
FMEA is a living document and if used correctly records:
• intellectual property
• weaknesses within the system
• quantified risk of system failure
• mistakes made
• solutions to problems
• responsibility for controls methods
Failure are any potential errors or defects within a process, design,
or part, especially ones that affect the ‘customer’, environment
and law.
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What is FMEA?
• 1949 – US Military (MIL-P-1649)
• 1963 – NASA
• 1965 – Aerospace Industry
• 1975 – Nuclear Industry
• 1977 – Ford Motor Company
• 1980 – DIN 25448
• 1986 – VDA Volume 4
• 1992 – Ford, Chrysler & GM
• 2008 – AIAG
Is universally accepted as an engineering tool
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Why do FMEA?
Cost reduction and increased profits
Demand for higher quality
Extended warranty periods
Product liability
Quality standard demands
Retention of knowledge
Make processes more robust
Enhanced communication within the business,
customer & suppliers
• Shorter development times
• Functional Safety & Reliability
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Application of FMEA
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Application of FMEA
There are two main schools of thought
about the methodology to use and which is
most effective?
• Rose with a different name
• Procedure
• Document formats
• Adherence to ISO / TS 16949
• Basis for ISO / TS 26262
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Application of FMEA
To get the best out of FMEA you should
have:
• Cross functional team
• FMEA Moderator / Facilitator
• Props and documentation
• Structured approach
• FMEA Software
• Management Support!
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A Structured Approach
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Effective FMEA
Step 1: Visual representation of the scope
Inner Race Spline
Inner Race
Inner Race Track
Inner Race Sphere
Outer Race Sphere
Outer Diameter
Outer Race
Outer Race Track
Outer Race Spline
Thread
CV Joint
Windows
Cage
Cage Sphere
Hole
ABS Ring
Ball Bearing
Grease
Clip
Shield
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Effective FMEA
Step 2: Runs in line with other engineering
techniques, such as Function Analysis System
Technique (FAST)
Capacitor #38
Filter noise
Accelerator input circuit
Conditions accelerator target wiper
signal
Electronic drive control
Sends a timely motor speed target to the
controllers
Monolithic integrated low dropout
voltage tracker
Mirrors input voltage to output voltage
Accelerator input circuit
Provides specified voltage stimulus for
the accelerator pedal target point
Capacitor #39
Filter noise
Diode #6
Protection
Programmed Microcontroller
Provides accelerator target stimulus
PCB circuit track
Maintain electrical continuity
Why?
Effects
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Mode
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How?
Causes
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Effective FMEA
Focus on functions provide guidance for the
analysis of failures, or step 3.
• Short
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Signal stuck at ground
Signal stuck at
specified voltage
Signal is corrupted
Accelerator input circuit
Conditions accelerator target wiper
signal
Electronic drive control
Sends a timely motor speed target to the
controllers
Monolithic integrated low dropout
voltage tracker
Mirrors input voltage to output voltage
Accelerator input circuit
Provides specified voltage stimulus for
the accelerator pedal target point
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•
Effects
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Open
Capacitor #38
Filter noise
Loss of Voltage stimulus
Corrupted Voltage
stimulus
Voltage stimulus when
not required
Mode
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Capacitor #39
Filter noise
Diode #6
Protection
Programmed Microcontroller
Provides accelerator target stimulus
PCB circuit track
Maintain electrical continuity
Causes
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Effective FMEA
Step 3: Efficient construction of effective possible
failure scenarios
Capacitor #38
Short
Monolithic integrated low dropout voltage
tracker
Output loss when input is high
Accelerator input circuit
Point of target wiper signal stuck at ground
Accelerator input circuit
Loss of voltage stimulus for accellerator
pedal target point
Diode #6
Shorted to ground
Diode #6
Open
Programmed Microcontroller
Output stuck low
PCB circuit track
Loss of electrical continuity
Effects
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Causes
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Effective FMEA
Step 4: Possible failure scenarios are displayed in a
fashion that is consistent with previous steps
Failure Effect(s)
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S
Failure Mode
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Failure Cause(s)
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Effective FMEA
AIAG form can be unintentionally misleading
Effects
Mode
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Causes
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Effective FMEA
E=MC2
VDA form is logical
Effects
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Mode
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Causes
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Effective FMEA
Step 4: Ensuring that only the controls that
are currently in fruition are considered when
calculating the risk
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Effective FMEA
Step 4: Analysis of the data using RPN is not
just 1-1000, there are 120 values that can
result from SxOxD, which may not reflect
criticality.
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Effective FMEA
Common sense shall prevail by looking at
the risk assessment results in a different way
e.g.:
Automotive
risk model
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Effective FMEA
Step 5: Reduction of the risk is displayed in a
Chronological order
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Effective FMEA
Create your own descriptions of the risk
factors of Severity (S), Occurrence (O) and
Detection (D):
• Reflect what you do as a business
• Reflect the product you make
• Is there a customer mandate?
• Using ‘rule of thumb’ statements &
benchmark examples
• Use AIAG descriptions as guidance*
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Use Software for FMEA
Due to the complexities of modern products
& processes, software is essential. Many
companies use MS Excel, but dedicated
software can provide a visual representation
of:
• the system analysed
• interfaces between sub-systems, plus inputs
and outputs
• complex relationships between the failures
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Use Software for FMEA
In addition to this dedicated software allows the
FMEA to:
• be filtered or colour coded according to your
own criteria
• produce additional statistical data and
additional quality documentation as a
consequence
• Switch easily between FMEA form layouts
• handles variances
• Supports delegation and tracking of
corrective measures
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Use an FMEA facilitator
• Experienced FMEA facilitation will ultimately
save time and make meetings more focused
& constructive.
• An experienced FMEA facilitation minimises
digression into different types of FMEA.
• An external FMEA facilitator may ask the
‘stupid questions’ that may have been
overlooked as they may be thinking outside of
the box
• An effective FMEA records intellectual capital
for the future developments (semantics)
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078 999 625 53 - 01785 711 296
[email protected]
Penkridge, Stafford, ST19 5TE. UK
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