FMEA - Failure Modes and Effects Analysis

What is Failure Modes and Effects Analysis?

Failure Modes and Effects Analysis is a systematic way to identify and either eliminate or mitigate risk.  It is forward-looking, which means that it is an effort to accurately predict and control the future.  This is important to make sure that an asset is being maintained efficiently and effectively.

What are the Benefits of FMEA?

• Greater safety and environmental integrity

• Improved performance

• Greater maintenance cost-effectiveness

• Longer useful asset life

• A comprehensive database of failure modes and spares

• A useful troubleshooting guide

• Better teamwork

• A comprehensive and uniform understanding of the asset

How Does Failure Modes and Effects Analysis Work?

It’s actually pretty straightforward.  There are seven steps:

1. What are the functions and associated performance standards of the asset in its present operating context?

What is the asset designed to do?  What do operators expect it to do?  And what is the context in which it is currently operating?  This first step clearly defines what the asset is capable of and what we expect of it.  This is important because it’s frequently the case that different stakeholders have different ideas as to how the asset works and what it is capable of.

If the asset is complicated, we need to break it down into systems, subsystems, and components.  Failures usually happen at the component level.  But normally we experience the results of a component failure at the asset level.  So we need a detailed breakdown of all the different layers that make up the asset.

2. In what ways could/would it fail to fulfil its functions?

Once we have the asset hierarchy defined, we then need to define all the ways it could fail to perform as designed/expected.  This requires a diverse team of knowledgeable experts.

3. What would cause these failures?

Next we examine the causes of these failures.  We call these causes “failure modes.”  We determine failure modes based on past experience and input from the team.

4. What are the effects of each failure?

Any given failure can have a variety of effects.  We examine the effects on the component, sub-system, and asset.

5. What are the consequences of each failure?

An effect is usually accompanied by consequences.  The team develops a detailed list of these consequences.

6. What can we do to predict, detect, or prevent each failure?

For each of the failure modes the team identifies, they then determine how the failure can be predicted in advance or how to prevent it altogether.  For instance, can a measuring device be installed which will give the maintenance team advanced knowledge of an impending failure?  How soon do they need to act in order to minimize the impact on operations?

7. What should be done if a proactive task cannot be found?

Finally, what should be done if a potential future failure cannot be predicted or a proactive task cannot be found?  It could be that nothing needs to be done if the consequence and probability of failure is low.  But if the consequence and probability of failure is high, maybe the system needs to be redesigned or replaced with a different system that is inherently less risky.

Can FMEA be applied to processes?

Yes, Failure Modes and Effects Analysis can also be applied to processes.  You follow the same basic steps, but substitute the process for the asset.  You can then break the process down into sub-processes and steps.