A SIMPLE DISCRETE APPROXIMATION FOR THE RENEWAL FUNCTION

In the paper we propose a simple discrete approximation for calculating the renewal function which is an important characteristic in the areas of reliability, maintenance and spare components inventory planning. The approximation enables easy and relatively accurate calculation of the renewal function irrespective of the type of the probability density function of component failure times. It is especially applicable to the peak-shaped functions (i.e. components are subject to wear-out failures) when the analytical solution for the renewal function hardly ever exists. To prove the usefulness of the approximation some numerical results are given.