Failure Mode Effect Analysis - FMEA

1. FMEA – FAILURE MODE
EFFECT ANALYSIS
SASIDHARAN
215116033
DOMS NITT

2. WHAT IS FMEA?
Failure Mode and Effects Analysis (FMEA) is a method designed to:
• Identify and fully understand potential failure modes and their causes, and the
effects of failure on the system or end users, for a given product or process.
• Assess the risk associated with the identified failure modes, effects and causes,
and prioritize issues for corrective action.
• Identify and carry out corrective actions to address the most serious concerns.
Source: Excerpted from Nancy R. Tague’s The Quality Toolbox, Second Edition, ASQ Quality
Press, 2004.

3. TYPES OF FMEA
1. System – focuses on global system functions
2. Design – focuses on components and subsystems
3. Process – focuses on manufacturing and assembly processes
4. Service – focuses on service functions
5. Software – focuses on software functions
6. Machinery - Focuses on how machinery that perform processes might fail.
Source: http://www.npd-solutions.com/fmea.html

4. Source: webinar- American Standards for Quality
training module

5. WAYS TO IDENTIFY FAILURE MODES
Source: webinar- American Standards for Quality
training module

6. ROOT CAUSE ANALYSIS
• Fish bone diagram
• Why-Why analysis
• Parato analysis
• 5W2H analysis
Source: Wikipedia

7. FMEA EXAMPLE – ATM MACHINE
Source: Website- American Standards for Quality

8. RPN
Risk Priority Number (RPN) is a measure used when assessing risk to help identify
critical failure modes associated with your design or process. The RPN values range
from 1 (absolute best) to 1000 (absolute worst). The FMEA RPN is commonly used in
the automotive industry and it is somewhat similar to the criticality numbers used in
Mil-Std-1629A. The graphic below shows the factors that make up
the RPN and how it is calculated for each failure mode.
Source: http://www.fmea-fmeca.com/fmea-rpn.html

9. RELIABILITY
Reliability is the probability of an item to perform a required function
under stated conditions for a specified period of time. Reliability is
further divided into mission reliability and logistics reliability
Source: DOD guide for achieving reliability, availability, and maintainability AUG 3,2005

10. WHEN TO USE RELIABILITY CALCULATIONS?
Stress Analysis:
• Prior to release of design to production.
• Prior to implementation of design changes.
Reliability Predictions:
• Reliability prediction should be done at all stages of design
• Early Design Stage: Reliability prediction may be a rough estimate.
• Late Design Stage: Reliability prediction is refined.
• Fielded system: Revised prediction can incorporate field data for future use.
Source: Reliability and its Application inTQM, IIT Roorker , Mitanshu Garg, Production Engg.

11. CASES 1 – MUSIC KEYBOARD MANUFACTURER
A robo was employed to check the durability of the keys in the keyboard, where
the robo arm continuously pressed and released a particular key until it gets faulty.
A counter attached with the arm takes count of number of press and release.
The count at which the key fails is taken and matched with the design and the point
of failure and the reason for failure is identified.
Source: TV Show – ”How they do it” in National Geography Channel

12. CASE 2 - ASHOK LEY LAND
A FMEA test was conducted in the door hinge of a truck, where an automatic
mechanism was arranged in such a way that the door assembly is made to open and
close number of times, and there was a digital counter was attached with it which takes
the number of times the door is opened and closed. This is done until the door hinge
makes noise which is the first indicator of wear. The process is repeated until the hinge
fails. Now the point of failure in the component is identified and the reason for it is
analyzed. This process is simulated in ANSYS software and the possible failure modes
are identified. If there is any correction to be made to improve the life of the hinge is
identified and necessary steps are taken.
By this method the components under warranty are tested and their warranty period are
decided
Source: Ashok Leyland Research center, Vellivayalchavadi, Chennai

13. CASE 3 - ASHOK LEY LAND
The possible reason for malfunction of components like dashboard panel, door
glass and other in-cabin components are vibration due to engine and vibration due
to pit in the road when the truck runs on it. So an arrangement is made to simulate
the vibration on the cabin of the truck with all interior components installed. Now
at what the point the rearview & side mirror gets loosen is found and similarly for
other components. Based on this analysis the components to be replaced during
the service time or run kms is found out and the recommendations are given.
Source: Ashok Leyland Research center, Vellivayalchavadi, Chennai

14. THANK YOU