2. Failure Mode Effect Analysis
FMEA is Defined as “It is a methodology to assess and
reduce risk in systems, products and services. It aims
to Define, identify, prioritize and eliminate known or
potential failures at an early stage as possible”.
Types of FMEA:
1. A System FMEA
2. A Design FMEA
3. The Process FMEA
4. The Service FMEA
3. Steps involved in FMEA procedure:
The general procedure of FMEA is given below . Specific
details may vary with the standards of the organization
or industry.
Step 1: Form a cross functional team of people with diverse
knowledge about the process, product or service.
Step 2: Identify the scope of FMEA.
Step 3: Fill in the identifying information at the top of the
FEMA format.
Step 4: Identify the functions of your scope.
Step 5: For each function , identify all the ways that it could
fail to happen.(i.e. potential failure modes)
4. Step 6: For each failure mode, identify all the
consequences on the system.
Step 7: Determine how serious each effect is. This is
referred to as severity rating(S).
Step 8: For each Failure mode, determine the potential root
causes.( use the Cause analysis tools)
Step 9: For each cause, determine the occurrence
rating(O).
Step 10: For each cause, identify current process
controls.
Step 11: For each control, determine the detection
rating(D).
5. Step 12: Ask the question ‘ Is this failure mode
associated with a critical characteristic? This
step is optional for most industries.
Step 13: Calculate the risk priority number(RPN)
as RPN=(S)x(O)x(D).
Step 14: Identify recommended actions.
Step 15: As actions are completed, note results and the
date on the FEMA Format. Also note new S,O
and D ratings and new RPN.
6. Advantages of FMEA:
Improve the quality, reliability and safety of a
product/process.
Improve company image and competitiveness.
Increase user satisfaction.
Reduce system development timing and cost
Collect information to reduce future failure modes.
Emphasize problem prevention
Minimize late changes and associated cost.
Catalyst for teamwork and idea exchange between
functions.
Reduce the possibility of same kind of failure in future.
7. FMEA Documentation:
The purpose of FMEA document is to allow all involved
engineers to have access to others thoughts and to
design and manufacture using this collective group
thoughts.
Tools of FMEA document:
1. Block Diagram
2. Boundary Diagram
3. Parameter Diagram or P-Diagram
4. Interface Matrix
8. The design of FMEA Document:
FMEA number
Item
Design Responsibility
Prepared by
Model Number/year
Key data
FMEA date
Core team
Item/ function
Potential Failure mode
Potential Effect(S) of
failure
Severity(S)
Classification (Class)
Potential Causes
Occurrence
Current Design Controls
Detection(D)
Risk priority Number
Recommended Actions
Responsibility and Target
Completion Dates
Actions Taken
Resulting RPN
