Abstract

Some optimization problems in reliability and maintenance need to iteratively evaluate the renewal function (RF) of a lifetime distribution and/or its integral. For such problems, an accurate RF approximation with a closed-form expression is preferred to a numerical evaluation method. A number of RF approximations have been developed in the literature but few can simultaneously meet the requirements of simplicity, accuracy and integrability. This article aims to fill this gap by proposing such a RF approximation for the Weibull distribution. The proposed approximation is particularly useful for practitioners to solve the optimization problems that involve the RF and/or its integral.