Thursday, May 10, 2012

Failure Mode and Effects Analysis – FMEA

Have you heard of the term “FMEA” before? FMEA was developed by the U.S. military in 1949, and used by NASA for Apollo space missions and by Ford to reduce the risks of failure. Other industries adopted FMEA methods and applied them to products and processes. Performance-improvement practitioners use FMEA to detect critical xs and prevent potential failure modes. It is extremely useful for six sigma practitioners and champions and we are going to use it as well!!!

Failure Mode and Effects Analysis – FMEA

FMEA reviews a process step by step and asks, “What can go wrong?” That’s the failure mode. It then asks what happens if it fails? Next, potential root causes of the failure are listed and the frequency of occurrence is determined. The ability to detect (or prevent) the failure is also reviewed for the current process.

These three criteria, Severity (S), Occurrence (O), and Detection (D), are rated on scales of 1 to 10, with a 1 representing only a minor incidence and 10 representing a catastrophic event for S, very frequent occurrence for O, or inability to detect the failure for D. The product of the three S*O*D ratings becomes the Risk Priority Number (RPN). Higher RPNs prioritize the need to eliminate the cause, reduce the frequency, or improve detection and prevention of the failure mode.
The second part of FMEA is to determine action steps to reduce the RPN for those items selected. Once actions are taken, the S*O*D ratings and the RPN are revised.

Most organizations develop rating scales specific to their processes, products, and services. Below is a sample FMEA Rating Scale for a Hospital or Healthcare Provider:

Things to Consider while building FMEAs:
The following are things that you must consider while you create/build the FMEA for your process. This will ensure that the output/outcome is neutral and useful to you and your project.
1. Conduct a FMEA for process steps that are key to improving your primary metric. Your project purpose is to investigate failure modes related to your primary metric, not to document all failures for each step of the entire process. Concentrate on areas that have high RPN values and those that are very high on the Severity Scale. Wasting time on low RPN or low Severity issues is not advisable, esp. if you are crunched for time.
2. Keep the team on track. Extensive review of potential causes in the first meeting or debates on exact ratings might slow the process down and you might be focusing too much attention on low RPN failure modes.
3. Remember that FMEA can be dominated by opinions. Gather data to support your ratings.
4. Keep the S*O*D rating scales in balance. Heavy weighting in one of the categories can bias the final RPN value.

Prev: Focus on Causes

Next: Prioritize Potential Causes

No comments:

Post a Comment

© 2013 by All rights reserved. No part of this blog or its contents may be reproduced or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without prior written permission of the Author.


There was an error in this gadget