Infrastructure asset management practitioners who are handling a network of “very poor condition” assets need to show decision-makers the amount needed to restore assets to “very good condition”. The use of an optimized decision model does just that.
The Deighton Water Model is able to demonstrate the significant difference between intervening while assets are in “fair and poor condition” levels and when they are already in “very poor” condition.
Faced with numerous assets in very poor or poor condition, asset owners have the tendency to go and fix these assets and expend many resources on them.
While doing this, some assets are also deteriorating to “fair” and “poor” condition and for optimal results intervention is also critical for these assets.
Focussing asset interventions on assets in very poor or poor condition might not be effective because it is like putting out a bushfire when the fire has spread and everything is already burned and damaged.
So there’s no better time than starting preventive maintenance at appropriate asset condition when you can still grab those assets back into very good condition.
Infrastructure Decision Support (IDS) of New Zealand has done some studies to compare “worst first” intervention and optimized intervention.
In their study, IDS compared a network projected forward through 15 to 20 years.
The network’s conditions were analyzed as it advanced through time. Intervention in the worst first year by year was compared with the intervention based on an optimized decision-making program.
The results of this analysis showed that a “worst first” strategy can be up to ten times more expensive in the medium term when compared to an optimized intervention strategy.
The key learning demonstrated from these studies, and reflected in the Deighton water model is that if you let your assets reach “very poor condition” level, it would cost a lot of energy and money to get them back up to any sort of good condition.
The range between “good” and “fair” conditions and up to “very good” is the optimal range to work in.
As an industry, we now have the tools and expertise to come up with an optimized decision-making program.
I would encourage you to investigate the use of these tools as part of your infrastructure asset management network.