An Integral Measure of Aging/rejuvenation for Repairable and Non–repairable Systems

This paper introduces a simple index that helps to assess the degree of aging or rejuvenation of repairable systems and non-repairable systems (components). The index ranges from –1 to 1. It is negative for the class of decreasing failure rate distributions and point processes with decreasing ROCOF and is positive for the increasing failure rate distributions and point processes with increasing ROCOF. The introduced index is distribution free. Index Terms – aging, rejuvenation, homogeneity, non–homogeneity. ACRONYMS CDF cumulative distribution function CFR constant failure rate CIF cumulative intensity function DFR decreasing failure rate GPR G–renewal process HPP homogeneous Poison process IFR increasing failure rate NHPP non–homogeneous Poison process PP point process ROCOF rate of occurrence of failures RP renewal process TTF time to failure