Note on relations between criteria for ageing

This work is focused on proving implications between criteria for ageing of a system with a well-defined survival time distribution. Specifically, two reliability measures, the mean residual lifetime (MRL) and the hazard rare (HR) are considered. The current article deals with the question of whethe r a specific property or criterion for ageing with respect to a reliability measure implies the same property or some other criterion with another rel iability measure. Implications of various criteria, additional consequences regarding various non-parametric classes of life distributions and particu lar features of MRL functions are derived and discussed using a characteriz ation result of such functions. (C) 2000 Elsevier Science Ltd. All rights r eserved.