Understanding Optimized Decision-Making Using the Deighton Water Model

Deighton is the company that develops and implements infrastructure asset management software, particularly optimized decision-making principles.

Deighton has partnered with IDS over the last 16 years in New Zealand to deliver an optimized decision tool for New Zealand public infrastructure engineers.

IDS is owned by New Zealand public infrastructure engineers through IPWEA NZ

Deighton created the water model to explain the effects of deteriorating asset conditions on your investment.

The water model has four buckets representing four typical conditions of an asset.

From the top bucket, these conditions are:

• very good
• fair
• poor
• very poor

The water inside the buckets represents our assets. As time goes on, the assets’ condition deteriorates from very good, to fair, to poor, to very poor. And you can see on the side of the buckets the water (investment) is flowing down to the bottom bucket.

Each bucket has a pump that brings in water symbolizing the investment needed to recover or restore assets to “very good condition”.

The “very poor condition” bucket has the biggest pumps among the four buckets because it takes much energy to pump up water to the top – up the “very good condition” bucket.

This illustrates the amount of investment necessary to restore assets. Yes, you will need a lot more money to restore your assets to a very good condition.

In the middle two buckets, the pumps are smaller than the “very poor condition” bucket. Also, the “fair condition” bucket pump is a bit bigger than the pump of the “poor condition” bucket.

The idea is to intervene before an asset deteriorates down to a very poor condition, which would be too costly to restore back to its very good condition. Maintaining assets at the top three buckets means achieving an optimal solution to our network management.

Preventive maintenance is one principle of infrastructure asset management, which must be implemented when assets are at “good” and “fair” conditions.

Studies revealed that assets left to deteriorate to “very poor condition” could cost up to ten times the amount of money or investment compared with the cost of the early intervention.

In the water model, the big pump size represents the up to ten times expenditure for bringing “very poor condition” assets back to their very good condition level. Deighton has done analysis and practical tests on this.

The water model that Deighton developed is based on the dTIMS software IDS is using.

It is one simple clear way of explaining the principles and dynamics of optimized decision managing, and the dTIMS software.