FMEA

Failure Mode, Effects, and Analysis
(F.M.E..A)
&
Why it is useful for Complex Facilities
By
Ojes Sai Pogiri
K-5870

INTRODUCTION TO FMEA
• A failure mode and effect analysis (FMEA)
is an engineering technique used to
define, identify, and eliminate known
and/or potential failures, problems,
errors, and so on from the system, design
process, and/or service before they reach
the customer (Omdahl 1988;ASQC 1983).
• Also called: potential failure modes and
effects analysis; failure modes, effects
and criticality analysis (FMECA)

INTRODUCTION TO FMEA
The FMEA will identify corrective actions required to prevent failures
from reaching the customer, thereby assuring the highest durability, quality, and
reliability possible in a product or service. A good FMEA:
• Identifies known and potential failure modes
• Identifies the causes and effects of each failure mode
• Prioritizes the identified failure modes according to the risk priority number
(RPN)—the product of frequency of occurrence, severity, and detection
• Provides for problem follow-up and corrective action

History
• The first widely known use of FMEAs was by
the US Military at the end of the 1940s. The
military developed the technique to reduce
sources of variation and corresponding
potential failures in the production of
munitions – and it proved a highly effective
tool.
• Once it was recognized that project risk was
reduced by the military’s use of FMEAs,
NASA adopted the methodology as a crucial
project planning technique as well. FMEAs
proved to be vital to the success of the
Apollo (and subsequent) NASA missions.
FMEAs are widely used by the civil aviation
industry to assess aircraft safety.

History
• The Civil aviation industry was an early adopter of FMEA
• During the 1970’s, use of FEMA and related techniques spread to other
industries. The Ford Motor introduced FMEA in automobile industry for safety
and regulatory consideration.
• In 1971 NASA prepared a report for the US geological survey recommending the
use of FMEA in assessment of offshore petroleum exploration.
• Now FMEA is extensively used in a variety of industries including semiconductor
processing, food service, plastics, software and healthcare.
• Adopted as part of APQP (Advanced Product Quality Planning).
• Required elements OF PPAP (Production Part Approval Process).
• Integrated into QS-9000 & ISO/TS 16949.

Benefits
• It provides a documented method for selecting a design with a high probability of
successful operation and safety.
• A documented uniform method of assessing potential failure mechanisms, failure
modes and their impact on system operation, resulting in a list of failure modes
ranked according to the seriousness of their system impact and likelihood of
occurrence.
• Early identification of single failure points (SFPS) and system interface problems,
which may be critical to mission success and/or safety. They also provide a
method of verifying that switching between redundant elements is not
jeopardized by postulated single failures.
• An effective method for evaluating the effect of proposed changes to the design
and/or operational procedures on mission success and safety.
• A basis for in-flight troubleshooting procedures and for locating performance
monitoring and fault-detection devices.
• Criteria for early planning of tests.

What is Failure
Mode and
Effects
Analysis
• Failure Mode and Effects Analysis (FMEA) is a
structured approach to discovering potential failures
that may exist within the design of a product or
process.
• Failure modes are the ways in which a process can
fail. Effects are the ways that these failures can lead
to waste, defects or harmful outcomes for the
customer. Failure Mode and Effects Analysis is
designed to identify, prioritize and limit these failure
modes.
• FMEA is not a substitute for good engineering.
Rather, it enhances good engineering by applying
the knowledge and experience of a Cross Functional
Team (CFT) to review the design progress of a
product or process by assessing its risk of failure.

Why to Perform FMEA
• Historically, the sooner a failure
is discovered, the less it will
cost. If a failure is discovered
late in product development or
launch, the impact is
exponentially more devastating.
• FMEA is one of many tools used
to discover failure at its earliest
possible point in product or
process design.

When to Perform FMEA
• When a process, product, or service is being designed or
redesigned, after quality function deployment (QFD)
• When an existing process, product, or service is being applied
in a new way
• Before developing control plans for a new or modified process
• When improvement goals are planned for an existing process,
product, or service
• When analyzing failures of an existing process, product, or
service
• Periodically throughout the life of the process, product, or
service

Who Conducts the FMEA
The FMEA is a team function and
cannot be done on an individual
basis.
The team must be defined as
appropriate for a specific project
and cannot serve as the universal
or company FMEA team. The
knowledge that is required for the
specific problem is unique to that
problem.

TYPES OF FMEA
DESIGN FMEA PROCESS
FMEA
SYSTEM FMEA SERVICE FMEA MACHINE
FMEA

Design FMEA
Design FMEA (DFMEA) explores the possibility of
product malfunctions, reduced product life, and safety
and regulatory concerns derived from:
• Material Properties
• Geometry
• Tolerances
• Interfaces with other components and/or
systems
• Engineering Noise: environments, user profile,
degradation, systems interactions

Process FMEA
Process FMEA (PFMEA) discovers failure that impacts
product quality, reduced reliability of the process,
customer dissatisfaction, and safety or environmental
hazards derived from:
• Human Factors
• Methods followed while processing
• Materials used
• Machines utilized
• Measurement systems impact on acceptance
• Environment Factors on process performance

System FMEA
A System FMEA is the highest-level analysis of an entire
system that is made up of various subsystems. The focus is
on:
• System-related deficiencies, including system safety,
system integration, interfaces or interactions
between subsystems or with other systems
• Interactions with the surrounding environment
• Human interactions
• Services
• Other issues that could cause the overall system not
to work as intended

Service FMEA
Service FMEA helps eliminate product failures due to improper
installation, operation, maintenance. A service FMEA is a structured
procedure for identifying and preventing service-related product
failures, i.e., failures due to improper installation, operation,
maintenance, or repair. The purpose of a service FMEA is to ensure
that:
• Service tools will perform as required
• All necessary instructions are provided
• Instructions are clear and cannot be misunderstood
• Individuals who provide the service understand their
responsibilities and know how to install, operate,
maintain, and repair the product.

Machine FMEA
Machine FMEA is a methodical approach used for identifying risks
associated with machinery and equipment failure. The purpose of
the MFMEA is to increase reliability of the machinery, reduce time
to repair and add prevention techniques, such as diagnostics.
MFMEA is an integral part of Total Predictive Maintenance
(TPM).The Machinery FMEA is applied when:
• A customer requests evidence to support reliability
targets for the machine
• A new technology or process is introduced
• A current process with modifications made to tooling /
equipment due to Kaizen, Lean or Cost of Quality projects
• A current machine is placed in a new environment or
different location

STEPS TO DEVELOP FMECA
Step 1:-FMECA prerequisites
1. Define the system to be analysed
• System boundaries (which parts should be
included, and which should not)
• Main system missions and functions (incl.
functional requirements)
• Operational and environmental conditions to be
considered
• Note: Interfaces that cross the design boundary
should be included in the analysis

Step 1:-FMECA
prerequisites
2. Collect available information that describes
the system to be analysed
• Including drawings, specifications,
schematics, component lists interface
information, functional descriptions, and
so on
3. Collect information
• About previous and similar designs from
internal
• and external sources; including FRACAS
data, interviews with design personnel,
operations and maintenance personnel,
component suppliers, and so on

Step 2:-System structure analysis
• Divide the system into manageable units - typically functional
elements. To what level of detail we should break down the system
will depend on the objective of the analysis. It is often desirable to
illustrate the structure by a hierarchical tree diagram:

In some applications it may be
beneficial to illustrate the system
by a functional block diagram
(FBD) as illustrated in the
following figure.

The analysis should be carried out on an as high level in the system
hierarchy as possible. If unacceptable consequences are discovered on
this level of resolution, then the element (subsystem, sub-subsystem,
or component) should be divided into further detail to identify failure
modes and failure causes on a lower level. To start on a too low level
will give a complete analysis but may at the same time be a waste of
efforts and money.

Step 3:-
Work
Sheet
• A suitable FMECA worksheet must be
decided. In many cases the client
(customer) will have requirements to
the worksheet format – for example
maintenance management system.
• For each system element (subsystem,
component) the analyst must consider
all the functions of the elements in all
its operational modes and ask if any
failure of the element may result in any
unacceptable system effect. If the
answer is no, then no further analysis
of that element is necessary. If the
answer is yes, then the element must
be examined further.

Step 3:- Work
Sheet
1. In the first column a unique reference to an element
(subsystem or component) is given. It may be a reference to an
id. in a specific drawing, a so-called tag number, or the name
of the element.
2. The functions of the element are listed. It is important to list
all functions. A checklist may be useful to secure that all
functions are covered.

Step 3:- Work Sheet
3. The various operational modes for the element are listed. Example
of operational modes are idle, standby, and running. Operational
modes for an airplane include, for example, taxi, take-of, climb,
cruise, descent, approach, flare-out, and roll. In applications where
it is not relevant to distinguish between operational modes, this
column may be omnified.
4. For each function and operational mode of an element the
potential failure modes have to be identified and listed. Note that a
failure mode should be defined as a nonfulfillment of the functional
requirements of the functions specified in column 2.

Step 3:- Work Sheet
5. The failure modes identified in column 4 are studied one-by-one. The
failure mechanisms (e.g., corrosion, erosion, fatigue) that may produce or
contribute to a failure mode are identified and listed. Other possible causes
of the failure mode should also be listed. If may be beneficial to use a
checklist to secure that all relevant causes are considered. Other relevant
sources include: FMD-97 “Failure Mode/Mechanism Distributions” published
by RAC, and OREDA (for offshore equipment).
6. The various possibilities for detection of the identified failure modes are
listed. These may involve diagnostic testing, different alarms, proof testing,
human perception, and the like. Some failure modes are evident, other are
hidden. The failure mode “fail to start” of a pump with operational mode
“standby” is an example of a hidden failure.

Step 3:- Work Sheet
• In some applications, an extra column is added to rank the likelihood
that the failure will be detected before the system reaches the
user/customer. The following detection ranking may be used
• The effects each failure mode may have on other components in the
same subsystem and on the subsystem as such (local effects) are
listed.
• Failure Modes are written as anti-functions or anti-requirements in
five potential ways:
• Full function failure
• Partial / degraded function failure

Step 3:- Work Sheet
• Intermittent function failure
• Over function failure
• Unintended function failure
• Effects are the results of failure, where each individual effect is given
a Severity ranking. Actions are considered at this stage if the Severity
is 9 or 10
• Recommended Actions may be considered that impact the
product or process design addressing Failure Modes on High
Severity Rankings (Safety and Regulatory)

Step 3:- Work Sheet
Potential Causes and Prevention Controls through Occurrence Ranking
• Causes are selected from the design / process inputs or past failures and
placed in the Cause column when applicable to a specific failure mode. The
columns completed in Path 2 are:
• Potential Causes / Mechanisms of Failure
• Current Prevention Controls (i.e. standard work, previously successful
designs, etc.)
• Occurrence Rankings for each cause
• Classification of Special Characteristics, if indicated
• Actions are developed to address high risk Severity and Occurrence
combinations, defined in the Quality-One Criticality Matrix

Step 3:- Work Sheet
• Development involves the addition of Detection Controls that verify that
the design meets requirements (for Design FMEA) or cause and/or failure
mode, if undetected, may reach a customer (for Process FMEA).
• The columns completed are:
• Detection Controls
• Detection Ranking
• Actions are determined to improve the controls if they are insufficient to
the Risks determined. Recommended Actions should address weakness in
the testing and/or control strategy.
• Review and updates of the Design Verification Plan and Report
(DVP&R)or Control Plans

Step 3:- Work Sheet
• RPN is calculated by multiplying the Severity, Occurrence and
Detection Rankings for each potential failure / effect, cause and
control combination. Actions should not be determined based on an
RPN threshold value. This is done commonly and is a practice that
leads to poor team behavior. The columns completed are:
• Review Recommended Actions and assign RPN for additional follow-
up
• Assign Actions to appropriate personnel
• Assign action due dates

Step 3:- Work Sheet
• The risk associated to
failure mode is a function
of the frequency of the
failure mode and the
potential end effects
(severity) of the failure
mode. The risk may be
illustrated in a risk
matrix.

Step 3:- Work Sheet
• Risk priority number:
• O = the rank of the occurrence of the failure mode
• S = the rank of the severity of the failure mode
• D = the rank of the likelihood the failure will be detected before the
• system reaches the end-user/customer.
• All ranks are given on a scale from 1 to 10. The risk priority number (RPN) is defined as
• RPN = S x O x D
• The smaller the RPN is better

Step 4:-Team Review
A design FMECA should be initiated by the design engineer, and the system/process
FMECA by the systems engineer. The team consist of Project manager
• Design engineer
• Test engineer
• Reliability engineer
• Quality engineer
• Maintenance engineer
• Field service engineer
• Manufacturing/process engineer
• Safety engineer

Step 4:-Team Review
Review objectives:
The review team studies the FMECA worksheets and the risk matrices and/or
the risk priority numbers (RPN). The main objectives are:
• 1. To decide whether the system is acceptable
• 2. To identify feasible improvements of the system to reduce the risk.
This may be achieved by:
• Reducing the likelihood of occurrence of the failure
• Reducing the effects of the failure
• Increasing the likelihood that the failure is detected before the system
reaches the end-user.

Step 5:-Selection of actions
After successful confirmation of Risk Mitigation Actions, the Core Team or
Team Leader will re-rank the appropriate ranking value (Severity, Occurrence
or Detection). The new rankings will be multiplied to attain the new RPN.
The original RPN is compared to the revised RPN and the relative
improvement to the design or process has been confirmed. Columns
completed in Step 7:
• Re-ranked Severity
• Re-ranked Occurrence
• Re-ranked Detection
• Re-ranked RPN
• Generate new Actions, repeating Step 5, until risk has been mitigated
• Comparison of initial RPN and revised RPN

Step 5:-Selection of actions
The risk may be reduced by introducing:
• Design changes
• Engineered safety features
• Safety devices
• Warning devices
• Procedures/training

FMEA Document Analysis
The analysis of an FMEA should include multiple level considerations,
including:
• Severity of 9 / 10 or Safety and Regulatory alone (Failure Mode
Actions)
• Criticality combinations for Severity and Occurrence (Cause
Actions)
• Detection Controls (Test and Control Plan Actions)
• RPN Pareto
When completed, Actions move the risk from its current position in the
Quality-One FMEA Criticality Matrix to a lower risk position.

RPN Action Priority
When risk is determined to be unacceptable, priority of action to be applied
as follows:
• Error Proofing (Eliminate Failure Mode or Address Cause)
• Failure Mode (Only Severity of 9 or 10)
• Causes with High Occurrence
• Improve Potential Process Capability
• Increase Tolerance (Tolerance Design)
• Reduce Variation of the Process (Statistical Process Control and Process Capability)
• Improve Controls
• Mistake Proofing of the tooling or process
• Improve the inspection / evaluation techniques

FMEA Relationship to Problem Solving
The Failure Modes in a FMEA are equivalent to the Problem Statement or
Problem Description in Problem Solving. Causes in a FMEA are equivalent to
potential root causes in Problem Solving. Effects of failure in a FMEA are
Problem Symptoms in Problem Solving. More examples of this relationship
are:
• The problem statements and descriptions are linked between both
documents. Problem solving methods are completed faster by utilizing
easy to locate, pre-brainstormed information from an FMEA.
• Possible causes in an FMEA are immediately used to jump start
Fishbone or Ishikawa diagrams. Brainstorming information that is
already known is not a good use of time or resources.

FMEA Relationship to Problem Solving
• Data collected from problem solving is placed into an FMEA for
future planning of new products or process quality. This allows an
FMEA to consider actual failures, categorized as failure modes and
causes, making the FMEA more effective and complete.
• The design or process controls in an FMEA are used in verifying the
root cause and Permanent Corrective Action (PCA).
• The FMEA and Problem Solving reconcile each failure and cause by
cross documenting failure modes, problem statements and
possible causes'

USES OF FMEA
• Development of system requirements that minimize thelikelihood of
failures.
• Development of methods to design and test systems to ensure that
the failures have been eliminated.
• Evaluation of the requirements of the customer to ensure that those
do not give rise to potential failures.
• Identification of certain design characteristics that contribute to
failures and minimize or eliminate those effects.
• Tracking and managing potential risks in the design. This helps avoid
the same failures in future projects.

Advantages of FMEA
• Catalyst for teamwork and idea exchange between functions
• Collect information to reduce future failures, capture engineering
knowledge
• Early identification and elimination of potential failure modes
• Emphasize problem prevention
• Improve company image and competitiveness
• Improve production yield
• Improve the quality, reliability, and safety of a product/process

Advantages of FMEA
• Increase user satisfaction
• Maximize profit
• Minimize late changes and associated cost
• Reduce impact on company profit margin
• Reduce system development time and cost
• Reduce the possibility of same kind of failure in future
• Reduce the potential for warranty concerns

Application Areas:
• Design engineering. The FMECA worksheets are used to identify and
correct potential design related problems.
• Manufacturing. The FMECA worksheets may be used as input to
optimize production, acceptance testing, etc.
• Maintenance planning. The FMECA worksheets are used as an
important input to maintenance planning – for example, as part of
reliability centred maintenance (RCM). Maintenance related problems
may be identified and corrected.

Limitations
• While FMEA identifies important hazards in a system, its results may not be
comprehensive, and the approach has limitations. In the healthcare
context, FMEA and other risk assessment methods, including SWIFT
(Structured What If Technique) and retrospective approaches, have been
found to have limited validity when used in isolation. Challenges around
scoping and organizational boundaries appear to be a major factor in this
lack of validity.
• If used as a top-down tool, FMEA may only identify major failure modes in
a system. Fault tree analysis (FTA) is better suited for "top-down" analysis.
When used as a "bottom-up" tool FMEA can augment or complement FTA
and identify many more causes and failure modes resulting in top-level
symptoms. It is not able to discover complex failure modes involving
multiple failures within a subsystem, or to report expected failure intervals
of particular failure modes up to the upper level subsystem or system.

Limitations
• They can only be used to identify single failures and not combinations
of failures.
• Failures which result from multiple simultaneous faults are not
identified by this.
• Unless adequately controlled and focused, the studies can be time
consuming.
• They can be difficult and tedious for complex multi-layered systems.
• They are not suitable for quantification of system reliability.

References
• D. H. Stamatis, FMEA from Theory to Execution,Second Edition
• https://en.wikipedia.org/wiki/Failure_mode_and_effects_analysis#Us
es
• https://quality-one.com/fmea/#Intro
• https://asq.org/quality-resources/fmea#Procedure
• https://www.slideshare.net/bowerj/fmea-introductionppt

Thank YouOjes Sai Pogiri
K-5870

FMEA

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