Condition or performance data needs to be collected with sufficient frequency and consistency to provide a representative view of the condition of the asset and to track how this changes over time. The data can then be used to support deterioration modelling.
In many cases, organizations may not know the age of an asset or component or how long ago a particular capital treatment was carried out. In these cases, it is necessary to use condition as a basis for estimating age, e.g. the asset is rated at 7 our of 10 and for assets that have been subjected to a similar rehabilitation treatment, it would be expected that with a condition rating of 7, the asset would be 5 years of age. Deterioration modelling is important in estimating and then monitoring the future performance of an asset or treatment, in particular when the asset will need to be replaced or treatments carried out (PIARC 2003, PIARC 2008-b).