Abnormalities versus Failures

What better way to spend an afternoon than to debate which came first, the chicken or the egg? One thing that cannot be debated, however, is the fact that abnormalities come before failures. This is a fact.

We are conditioned early on to react to failures, the loss of function, why did the lights go out? Why did my car stop working? The abnormalities that lead to these failures often fly below our radar. This ability to change our thinking or refine our attention to look for abnormalities is the first critical step in transforming from a reactive to a proactive organization. Reactive organizations attribute their performance to bad luck, proactive organizations make their own luck.

So, what is the difference between an abnormality and a failure? First, I prefer to use the phrase “functional failure” rather than simply “failure.” I must concentrate and force myself to use these words, but it has an important effect on my thinking and the thinking of those around me. To me, failure seems to be an arbitrary word open to interpretation. On the other hand, loss of function or functional failure is quite clear; I can no longer do what I desire.

If the lightbulb goes out, I can no longer read my book – loss of function. If the impeller wears on my pump and can no longer produce my product in the required quantity – loss of function. If my tire goes flat and I can no longer drive my car at full speed – loss of function. In each case, if we start with that condition we desire, the loss of this ability or function becomes quite clear.

Abnormalities, on the other hand, are the clues that our assets provide to us that something is wrong and that we are on that pathway to losing our desired function. They are like a baby crying. Something is wrong, and as caretakers of our assets (our babies), it is our job to do something about it; proactively before functional failure occurs.

This pathway to functional failure and the abnormalities that mark this path are best described by the P-F curve shown below. Its explanation is quite simple and powerful at the same time. Let's take a look:

  • The vertical axis represents our equipment condition, while the horizontal axis represents time.
  • The higher the equipment condition, the better.
  • The first point on the graph (upper left-hand corner) is “the point where the failure starts to occur.” Let's consider this point P. Imagine that we forget to lubricate the bearings on an electric motor. Eventually, all the grease will evaporate out, leaving metal-to-metal contact. This is point P in this example.
  • The equipment (asset) starts to degrade, losing its condition slowly at first but then increasing in speed as time continues. As this process continues, the equipment provides clues that inform us of what is happening – at first, very subtle clues but increasing in magnitude (and our urgency, I hope) as the process continues. These clues are the abnormalities.
  • If we do not act proactively to the abnormalities, we will reach the point labeled “catastrophic failure.” This is point F, or the point of functional failure.
  • Because we have failed to react proactively to the abnormalities, we will now have to react to the functional failure – the choice has been made for us!
P-F Curve

What should we do about abnormalities? We must report them in an official way as soon as we see them. When I say "reporting in an official way", I mean something like putting a work request into our computerized maintenance management system (CMMS) or using an abnormality tag that is part of our operator care process.

Tugs on the shirtsleeve, emails, phone calls, sticky notes, none of these count. This collection of official notifications represents what we know to be our backlog, and a full and rich backlog is critical to our proactive approach to maintenance.

I talk to many people who tell me, "I only want people to report the important or critical problems". Guess what? Today’s unimportant problem will quickly become tomorrow’s important one. The P-F curve illustrates this perfectly.

Better to have a solid reporting system, a simple method to prioritize work so we are attacking the most important abnormalities first, as well as a robust and visual means to communicate our progress to everyone who participates in the process (managers, technicians, operations, and maintenance).

If we do not report abnormalities early or strive to report only those ambiguous “really important ones,” we sell ourselves short. When we fail to report abnormalities early, we lose the ability to address them early.

The most important thing to remember is this: all abnormalities eventually become functional failures. It is our choice to address them on our terms (proactively) or when the equipment demands it (reactively).

About the Author

Mike Gehloff

Mike Gehloff

Mike Gehloff has worked in the maintenance and reliability discipline for over 30 years with a wide range of experience both as a practitioner and a consultant. His area of expertise lies within the social sciences related to the discipline, particularly in the work control (maintenance planning and scheduling), operator care, and management systems areas.

Mike has worked extensively in the steel industry and held several corporate and division-level reliability positions. He also has experience in the mining, food and beverage, oil and gas, and power generation industries with a proven track record of delivering results. Mike is particularly effective in team-based environments where frontline associates are empowered to make a change in their organization. Breaking down barriers to communication, motivation, and a set of common goals for the organization are all areas that represent a professional passion for Mike.

Mike graduated from Eckerd College. He is a Certified Maintenance and Reliability Professional (CMRP), as well as a Certified Plant Maintenance Manager (CPMM). Mike is also a Six Sigma Black Belt and has earned a Master of Business Administration from the University of Florida. Mike is always open to adventure and has an extensive international travel resume.

Connect with Mike on LinkedIn.


Allied Reliability provides asset management consulting and predictive maintenance solutions across the lifecycle of your production assets to deliver required throughput at lowest operating cost while managing asset risk. We do this by partnering with our clients, applying our proven asset management methodology, and leveraging decades of practitioner experience across more verticals than any other provider. Our asset management solutions include Consulting & Training, Condition-based Maintenance, Industrial Staffing, Electrical Services, and Machine Reliability.

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