What is criticality analysis in maintenance?

Criticality analysis is a measurement used to prioritize assets in maintenance planning. It takes a combination of the seriousness of a potential failure with the failure’s frequency of occurrence and creates a rating of how critical a given asset is.

Component 1: Seriousness

The first component of criticality analysis is the seriousness of an event. In other words, it answers the question, “If this asset were to fail, how serious would the impact be?”

Of course, this is partly dependent on how critical the asset is to your processes, but there are other factors to consider as well, such as:

  • Safety implications of the failure
  • Cost and time to repair
  • Environmental impacts
  • Effects on product quality

If an asset’s failure wouldn’t necessarily cause severe disruption to your processes, it could still be serious if it presents a significant risk to your employees or to the environment.

Component 2: Frequency

The second component of criticality analysis is the frequency of a given failure. While certain equipment failures could be quite serious, they might be highly unlikely as well. As such, it might not make as much sense to prioritize preventive maintenance.

If a given failure mode turns out to be fairly likely, it might be worth prioritizing, especially if it would have a more severe impact.

Putting the two together

Neither of these two components gives a full picture of criticality analysis on its own. Just because a certain failure mode is likely doesn’t mean it’s always worth the cost of prevention, while more severe failures may be too infrequent to worry about.

As such, the ratings you give for both the seriousness and the frequency of a given equipment failure mode would be multiplied together to show an asset’s level of criticality.

Using criticality analysis

While each facility handles the exact process of criticality analysis a little differently, it’s an important part of maintenance planning. When prioritizing preventive maintenance tasks, determining assets to monitor for predictive maintenance, or evaluating schedule compliance, knowing the criticality of an asset will help you take care of the most important items first.