On the reliability importance of system components

In reliability theory, some measures are introduced , called importance measures, to evaluate the relative importance of individual components or groups of components in a system. Importance measures are quantitive criteria that ranke the components according to their importance. In the literature, different importance measures are presented based on different scenarios. These measures can be determined based on the system structure, reliability of the components and/or component liftime distributions. The purpose of this paper is the study different importance measures of the components of a system in reliability theory.