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Fmea Worksheet document sample
Document Sample
Process Failure
Mode Effect
Analysis
CA/PA-RCA : Advanced Tool
Northrop Grumman Corporation
Integrated Systems
Overview Objective
Failure Mode Effect Analysis (FMEA) – Provide a Basic
familiarization with a tool that aids in quantifying
severity, occurrences and detection of failures, and
guides the creation of corrective action, process
improvement and risk mitigation plans.
2
Agenda
FMEA History
What IS FMEA
Definitions
What it Can Do For You
Types of FMEA
Team Members Roles
FMEA Terminology
Getting Started with an FMEA
The Worksheet
FMEA Scoring
3
Agenda Why does it always
seem we have plenty of
time to fix our
problems, but never
enough time to prevent
the problems by doing
it right the first time?
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FMEA History
This “type” of thinking has been around for
hundreds of years. It was first formalized in
the aerospace industry during the Apollo
program in the 1960’s.
Initial automotive adoption in the 1970’s.
Potential serious & frequent safety issues.
Required by QS-9000 & Advanced Product Quality Planning Process
in 1994.
For all automotive suppliers.
Now adopted by many other industries.
Potential serious & frequent safety issues or loyalty issues.
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What is FMEA ?
Cause & effect, Root Cause Analysis,
Fishbone Diagram Etc
Failure Mode Effect Analysis
6
What is FMEA ?
Definition: FMEA is an Engineering “Reliability Tool” That:
Helps define, identify, prioritize, and eliminate known and/or
potential failures of the system, design, or manufacturing process
before they reach the customer. The goal is to eliminate the Failure
Modes and reduce their risks.
Provides structure for a Cross Functional Critique of a design or a
Process
Facilitates inter-departmental dialog.
Is a mental discipline “great” engineering teams go through, when
critiquing what might go wrong with the product or process.
Is a living document which ultimately helps prevent, and not react
to problems.
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What is FMEA ?
What it can do for you!
1.) Identifies Design or process related Failure Modes before they
happen.
2.) Determines the Effect & Severity of these failure modes.
3.) Identifies the Causes and probability of Occurrence of the
Failure Modes.
4.) Identifies the Controls and their Effectiveness.
5.) Quantifies and prioritizes the Risks associated with
the Failure Modes.
6.) Develops & documents Action Plans that will occur to
reduce risk.
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Types of FMEAs ?
System/Concept “S/CFMEA”- (Driven by System functions) A
system is a organized set of parts or subsystems to accomplish one
or more functions. System FMEAs are typically very early, before
specific hardware has been determined.
Design “DFMEA”- (Driven by part or component functions) A
Design / Part is a unit of physical hardware that is considered a
single replaceable part with respect to repair. Design FMEAs are
typically done later in the development process when specific
hardware has been determined.
Process “PFMEA”- (Driven by process functions & part
characteristics) A Process is a sequence of tasks that is
organized to produce a product or provide a service. A
Process FMEA can involve fabrication, assembly, transactions
or services.
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Types of FMEAs ?
System/Concept “S/CFMEA”- (Driven by System functions) A
system is a organized set of parts or subsystems to accomplish one
or more functions. System FMEAs are typically very early, before
specific hardware has been determined.
Design “DFMEA”- (Driven by part or component functions) A
Design / Part is a unit of physical hardware that is considered a
single replaceable part with respect to repair. Design FMEAs are
typically done later in the development process when specific
hardware has been determined.
Process “PFMEA”- (Driven by process functions & part
characteristics) A Process is a sequence of tasks that is
organized to produce a product or provide a service. A
Process FMEA can involve fabrication, assembly, transactions
or services.
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The FMEA Team Roles
Champion / Sponsor
Provides resources & support
Attends some meetings
Promotes team efforts
Shares authority / power with team
Kicks off team
Implements recommendations
FMEA Core Team Facilitator
Team Leader 4 – 6 Members “Watchdog“ of the process
“Watchdog” of the project
Good leadership skills Keeps team on track
Expertise in Product / Process FMEA Process expertise
Respected & relaxed Cross functional
Leads but doesn’t dominate Encourages / develops team dynamics
Honest Communication Communicates assertively
Maintains full team participation Active participation
Typically lead engineer Ensures everyone participates
Positive attitude
Respects other opinions
Participates in team decisions
Recorder
Keeps documentation of teams efforts
FMEA chart keeper
Coordinates meeting rooms/time
Distributes meeting rooms & agendas
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FMEA Terminology
1.) Failure Modes: (Specific loss of a function) is a concise
description of how a part , system, or manufacturing process may
potentially fail to perform its functions.
2.) Failure Mode“Effect”: A description of the consequence or
Ramification of a system or part failure. A typical failure mode may
have several “effects” depending on which customer you consider.
3.) Severity Rating: (Seriousness of the Effect) Severity is the
numerical rating of the impact on customers.
When multiple effects exist for a given failure mode, enter the worst
case severity on the worksheet to calculate risk.
4.) Failure Mode“Causes”: A description of the design or process
deficiency (global cause or root level cause) that results
in the failure mode .
You must look at the causes not the symptoms of the failure. Most failure
Modes have more than one Cause.
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FMEA Terminology (continued)
5.) Occurrence Rating: Is an estimate number of frequencies or
cumulative number of failures (based on experience) that will
occur (in our design concept) for a given cause over the intended
“life of the design”.
6.) Failure Mode“Controls”: The mechanisms, methods, tests,
procedures, or controls that we have in place to PREVENT the
Cause of the Failure Mode or DETECT the Failure Mode or Cause
should it occur .
Design Controls prevent or detect the Failure Mode prior to engineering
release
7.) Detection Rating: A numerical rating of the probability that a given
set of controls WILL DISCOVER a specific Cause of Failure Mode to
prevent bad parts leaving the facility or getting to the ultimate customer.
Assuming that the cause of the failure did occur, assess the capabilities of the
controls to find the design flaw..
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FMEA Terminology (continued)
8.) Risk Priority Number (RPN): Is the product of Severity,
Occurrence, & Detection. Risk= RPN= S x O x D
Often the RPN’s are sorted from high to low for consideration in the action planning
step (Caution, RPN’s can be misleading- you must look for patterns).
9.) Action Planning: A thoroughly thought out and well developed
FMEA With High Risk Patterns that is not followed with corrective
actions has little or no value, other than having a chart for an audit
Action plans should be taken very seriously.
If ignored, you have probably wasted much of your valuable time.
Based on the FMEA analysis, strategies to reduce risk are focused on:
Reducing the Severity Rating.
Reducing the Occurrence Rating.
Reducing the detection Rating.
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Getting Started on FMEA
What Must be done before FMEA Begins!
Understand your
=QFD
Ready?
Customer
Needs
Develop & Evaluate
Product/Process =Brain Storming
Concepts
Create =4 to 6 Consensus Based Multi Develop and
an Effective Drive
Level Experts 7
FMEA Team Determine
“Effects” of3 Action Plan
= What we The Failure
Define the FMEA are and are
Scope Mode
not working Severity Rating
Determine1 2 Determine 4 Determine5 6
6
Determine “Causes” of
Product or “Controls” Calculate &
Failure Modes The Failure
Process Assess Risk
of Function Mode
Functions Detection Rating
Occurrence Rating
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The FMEA Worksheet
Resp. & p p p p
Product S O D R
Failure Failure Actions Target S O D R
or E Causes C Controls E P
Mode Effects / Plans Complete E C E P
Process V C T N
Date V C T N
1 2 3 4 5 6 7
Develop
Determine Determine Determine
and
Product or “Effects” of “Controls”
Drive
Process The Failure Detection
Action Plan
Functions Mode Determine Rating
Severity “Causes” of
Determine Rating The Failure Calculate
Failure Mode &
Modes Occurrence Assess
of Function Rating Risk
If an FMEA was created during the Design Phase of the Program, USE IT!
Create an Action Plan for YOUR ROOT CAUSE
and Re-Evaluate the RPN Accordingly
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FMEA Scoring
Severity
Severity of Effect Rating
May endanger machine or operator. Hazardous without warning 10
Extreme
May endanger machine or operator. Hazardous with warning 9
Major disruption to production line. Loss of primary function, 100% scrap. Possible jig lock and
8
High
Major loss of Takt Time
Reduced primary function performance. Product requires repair or Major Variance.
Noticeable loss of Takt Time 7
Medium disruption of production. Possible scrap. Noticeable loss of takt time.
6
Moderate
Loss of secondary function performance. Requires repair or Minor Variance
Minor disruption to production. Product must be repaired.
Reduced secondary function performance. 5
Minor defect, product repaired or "Use-As-Is" disposition. 4
Fit & Finish item. Minor defect, may be reprocessed on-line. 3
Low
Minor Nonconformance, may be reprocessed on-line. 2
None
No effect 1
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FMEA Scoring
Occurrence
Failure Capability
Likelihood of Occurrence Rate (Cpk) Rating
Very High
1 in 2 < .33 10
Failure is almost inevitable
1 in 3 > .33 9
1 in 8 > .51 8
High
Process is not in statistical control.
Similar processes have experienced problems.
1 in 20 > .67 7
1 in 80 > .83 6
Moderate
Process is in statistical control but with isolated failures.
Previous processes have experienced occasional 1 in 400 > 1.00 5
failures or out-of-control conditions.
1 in 2000 > 1.17 4
Process is in statistical control. 1 in 15k > 1.33 3
Low
Process is in statistical control. Only isolated 2
failures associated with almost identical processes. 1 in 150k > 1.50
Remote
Failure is unlikely. No known failures associated 1 in 1.5M > 1.67 1
with almost identical processes.
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FMEA Scoring
Detection
Very Low Likelihood that control will detect failure Rating
No known control(s) available to detect failure mode. 10
9
Low
Controls have a remote chance of detecting the failure.
8
7
Moderate
Controls may detect the existence of a failure 6
5
Controls have a good chance of detecting the existence 4
High
of a failure
3
Very High
The process automatically detects failure. 2
Controls will almost certainly detect the existence of
a failure. 1
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FMEA Scoring
RPN or Risk Priority Number
The Calculation !
Severity x Occurrence x Detection= RPN
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Failure Modes & Effect Analysis
(FMEA) Part or Process Improvement
FMEA is a technique utilized to define, identify, and eliminate known or
potential failures or errors from a product or a process.
Identify each candidate Part or Process, list likely failure mode, causes,
and current controls
Prioritize risk by using a ranking scale for severity, occurrence, and
detection
Mitigate risk – Can controls be added to reduce risk? Recalculate RPN.
Characteristics with high Risk Priority Numbers should be selected for
Improvement and Action Plans Created
Recalculate RPN After Completion of Action Plans to Validate
Improvements
Resp. & p p p p
Product S O D R
Failure Failure Actions Target S O D R
or E Causes C Controls E P
Mode Effects / Plans Complete E C E P
Process V C T N
Date V C T N
120
Hole Oversize Unable to Wrong Ball Gage Kit Drill
Drilling Hole Install BP 5 Drill Bit 8 Visual Insp 3 Bits
010103 51 1 5
Fastener Used
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Failure Modes & Effect Analysis
Questions?
Call or e-mail:
Kevin M. Treanor Bob Ollerton
310-863-4182 310-332-1972/310-350-9121
kevin.treanor@ngc.com robert.ollerton@ngc.com
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