This document provides an overview of Failure Mode and Effects Analysis (FMEA). FMEA is a systematic process used to evaluate potential failures in a design, manufacturing or process and identify actions to address or prevent these failures. It involves identifying potential failure modes and ranking them based on severity, occurrence likelihood and ability to detect. Actions are then recommended to reduce the highest risk failures based on their Risk Priority Number. FMEA is intended to be preventative and identify issues before they occur.

1. FMEA
FAILURE MODE AND
EFFECTS ANALYSIS

2. WHAT IS AN FMEA
• A systematic group of activities intended to :
a) Recognize and evaluate the Potential failure of a
product / process and its effects of that failure.
b) Identify actions that could eliminate or reduce the
chance of the potential failure occurring
c) Document the entries process
FMEA IS PROACTIVE AND PREVENTS FAILURES
BEFORE THEY OCCUR.

3. FMEA
Is an action before –the – event.
Is not an exercise after the fact.
BENEFITS OF FMEA:
• Identifies potential problems with customer point of
view.
• Predictive & Preventive
• Prioritized the variables to be focused.

4. Three basic cases for which FMEA`s are generated:
1. New design , New technology, or new process.
2. Modifications to existing design or process.
3. Use of an existing design or process in a new
environment , location or application.
CATEGORIES OF FMEA
• DESIGN FMEA (DFMEA)
• PROCESS FMEA (PFMEA)

5. WHAT IS DESIGN FMEA ?
An analytical technique used by a design team as a means
to assure to extent possible, potential failure modes and
Their associated causes and mechanism have been
Considered and addressed and follow up actions taken
during Design phase.

6. WHAT IS PROCESS FMEA?
An analytical technique used by manufacturing / assembly
Team as a means to ensure to the extent possible that
potential failure mode and associated mechanism have
been considered and addressed and follow up action taken
before tooling for production.

7. WHEN TO DO FMEA?
1. Design FMEA should be initiated before or at design
concept finalisation.
2. Process FMEA should be initiated before or at the
feasibility stage prior to tooling for production.
3. FMEA`s are living documents.
4. When major changes to design or process are carried
out the FMEA should be reviewed or completed.
5. SPECIAL MENTION
FMEA`s should be continuously updated as changes
occur and new information is obtained.

8. DEFINATIONS:
POTENTIAL FAILURE MODE :
Is the manner in which a component sub system could
potentially fail to meet the process requirements and /
or design intent.
POTENTIAL EFFECTS OF FAILURE :
Is the defined as effects of failure as perceived by the
customer (internal or external)
What the customer might notice or experience.
The intent is to forecast the failure effects .

9. SEVERITY :
Is an assessment of the effects of failure mode on the
next component, subsystem or customer to be estimated
on scale of 1to10.
A reduction in severity ranking index can be effected
only through a design change.
POTENTIAL CAUSE MECHANISM OF FAILURE:
Is the indication of design weakness (DFMEA) or
specific deficiency in process (PFMEA)
.

10. OCCURANCE :
Is defined as the probability that a specific cause will
occur .To be ranked on a scale of 1to10.
Preventing or controlling the causes / mechanism of
failure through design or process change is the only
way a reduction in the occurrence ranking .

11. CURRENT DESIGN / PROCESS CONTROLS:
These are the activities e.g design verification /
validation measures which currently assure the design
adequacy for failure mode.
Two type of Design / Process controls:
Prevention: Reduce the rate of occurrence
Detection: Leads to corrective actions
The preferred approach is to first use prevention
controls, if possible.

12. CURRENT DESIGN / PROCESS CONTROLS:
The initial occurrence ranking will be affected by the
prevention controls provided they are integrated as part
of the design / process intent.
The initial rankings for detection will be based on
design / process controls that either detect the cause /
mechanism of failure , or detect the failure mode
Once the Design / Process controls have been identified,
review all prevention controls to determine if any
occurrence rankings need to be revised.

13. DETECTION:
Is the rank associated with the best detection control
listed in the design / process control.
Detection is a relative ranking, within the scope of
individual FMEA.
In order to achieve a lower ranking , generally the
planned design / process control has to be improved

14. DETECTION:
Random quality checks are unlikely to detect the
existence of an isolated defect and should not influence
the detection ranking.
Sampling done on a statistical basis is a valid detection
controls.

15. RISK PRIORITY NUMBER (RPN)
The RPN is an overall measure of design risk / Process
deficiency.
The risk priority number is the product of severity (s) ,
occurrence (o), and detection (d) rankings.
RPN = S X O X D

16. RECOMMENDED ACTION (S):
Preventive / Corrective action should be first directed
at high severity , high RPN, and other items designated
by the team.
The intent of any recommended action is to reduce
ranking in following order severity, occurrence and
detection.
If severity is 9 or 10 special attention must be given to
ensure that the risk is addressed through existing design
action / controls or process prevention / corrective
action regardless of the RPN

17. RECOMMENDED ACTION (S):
In case where the effect of an identified potential
failure mode could be a hazard to manufacturing /
assembly personnel.
Preventive / corrective action actions should be
taken to avoid the failure mode by eliminating or
controlling the cause(s) , or appropriate operator
protection should be specified.
Intent is to reduce severity , then occurrence and
then detection.

18. RECOMMENDED ACTION (S):
To reduce the probability of occurrence , process and
or design revision is required.
Only a design and / or process revision can being
about a reduction in the severity ranking.
Reduction in the detection ranking is the use of error
/ mistake proofing methods.

19. RESPONSIBILITY FOR THE RECOMMENDED
ACTION(s) :
Enter the individual responsible for the
recommended action and the target completion date.
ACTION(s) TAKEN :
After the action has been implemented . Enter a
brief description of the actual action and effective
date.

20. ACTION RESULTS :
After the preventing / corrective action has been
identified. Estimate and records the resulting
severity , occurrence and detection rankings.
Recalculate the RPN.
If no action are taken leave the related ranking
columns blank.
if further action is considered necessary , repeat the
analysis. The focus should always be on continuous
improvement

21. FMEA IS A LIVING DOCUMENT AND
SHOULD ALWAYS REFLECT THE
LATEST DESIGN LEVELAS WELL
AS THE LATEST RELEVANT
ACTIONS,INCLUDING THOSE
OCCURING AFTER THE START OF
PRODUCTION.

22. HOW TO DEVELOP FMEA ?
1. Assemble a team (cross functional)
2. Assign responsibilities.
3. Develop a flow diagram / Block diagram for Process
/ Product.
4. Collected data / Information.
5. Arrive at RPN for each potential cause of failure

23. HOW TO DEVELOP FMEA ?
6. Based on pareto rankings of RPN for respective
potential cause of failure priorities preventive action
directed first at highest ranks RPN and severity
Rank
7. Formulate the recommended / Preventive action for
potential failure cause after examining the
inadequacy of the present / current design and
process controls.

24. HOW TO DEVELOP FMEA ?
7. Implement action and records results.
8. Estimate and record the new resulting severity ,
occurrence and detection rankings and calculate
RPN. If necessary go back to step1.

25. POTENTIAL FAILURE MODE
DEVELOPMENT OF FMEA
For each item (-function) or process ask : what could go wrong?
Then identify
Then ask How could this happen? What could result of this!
Then identify
POTENTIAL CAUSE OF FAILURE POTENTIAL EFFECT OF FAILURE
Then ask :
How frequently could this happen? How important could this be?
Is this cause easy to detect?
Then identify
OCCURENCE DETECTION SEVERITY
Now calculate
RPN And take appropriate actions staring
with highest RPN`s …..