Decay Curves: Predicting Failure Before It Happens

A decay curve (also called a deterioration curve) maps an asset's condition against its age. It is not a prediction that a specific asset will fail on a specific date — it is a probability distribution over failure age, built from the shared behaviour of a population of similar assets. The core idea: most assets don't fail at a fixed age. They fail across a spread of ages clustered around some typical life. The shape and width of that spread is exactly what a decay curve encodes. This is what makes the method asset-agnostic. The same curve family that describes a cast iron water main also describes a roof membrane, a switchboard, or a concrete culvert — only the parameters change.

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