When thinking about the different ways of doing maintenance, we often consider either taking a time-based approach, or taking the focus only on the condition of our assets. But what role does criticality play in the decision-making? How well are we able prioritize keeping the supply to a, say, hospital in the best possible condition?
Teemu explains: “So to really make use of reliability-centered maintenance for linear assets, you need a network model with connectivity.” This means having the ability to trace the network, going through each network component, to determine that if this component fails, which parts of the network the failure affects, and how. “Of course, anyone can tell the importance of keeping your main transformers feeding your main supply lines in a good condition,” Teemu continues: “But tracing down the network, the task becomes more and more difficult. The computerized analysis allows utilities to discover the components that other network parts actually rely on for their supply.” The analysis also examines the reserve connections and probable outage durations, all aiming at reducing your down times.
So, one crucial aspect for distribution reliability is examining where the effects of a failure would be the highest. But what’s considered the highest depends on who’s looking at it. Product manager Eero Saarijärvi points out: “Modeling outages and the customer impacts they cause is a multifaceted issue. What is valued depends on the operational environment, and how it’s measured should be set accordingly.”
IN THE SPOTLIGHT
One approach is naturally the outage cost and duration - you know, your SAIDI, CAIDI, and so on. “In terms of maintenance, we’re looking at picking out network components for which the outage cost is above a certain level, and prioritizing them in our maintenance plans,” says Teemu.
That is to say that we should look at the disadvantage caused by an outage beyond the costs, especially when it comes to securing the supply to the most critical facilities of our society. And it’s not just the hospitals - for instance, I recently learned that the chicken at a farm can suffocate to death in hours if their ventilation is cut off by a power break. Let us not do that!
Holism & Integrations: Maintenance planning - financially
Of course, the modern day networks have the critical parts backed up with a reserve connection, reserve generators and maybe an UPS (such good news for the chicken!), but Teemu emphasizes that going for risk-based maintenance in your work planning will still pay off. “It is absolutely beneficial, because it provides utilities an efficient way to look at the entire network and prioritize maintenance for the assets that are maybe more important than others.”
So it does come back to the money. The point that Teemu and Eero are trying to bring across is really in helping utilities to reach for total-cost maintenance. You look at the entire network lifecycle, and match that with the resources you have - long-term. Teemu adds: “It increases your efficiency, when you know how to better direct your efforts to where it’s most needed.”
Now where it gets really cool is when you mix that with analyzed 3D data from airborne lidars, thermal ratings, infrared, and so on - some of what the NM Group is doing - that’s where your network model brings your maintenance to a whole new level, augmenting the risk-based analysis with an understanding on the asset criticality.
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