Statistics for Maintenance Modelling: Continuous Lifetime Distributions 2

# The Hazard Function for the Pareto Distribution¤

The hazard function is just the reciprocal function h(t) = . Hence the hazard rate decreases with t which means that the Pareto distribution is only appropriate where an item becomes more reliable with age.

The Pareto distribution gives rise to curves similar to the tail of the lognormal distribution and has the advantage that the equations for the reliability and hazard functions are much simpler. However while the Pareto may fit the tail of the data well, the lognormal often gives a better overall fit as it can model an early peak as well as the tail, e.g. when modelling incomes.

Click here to find out how to calculate the Pareto distribution in Excel.