‎Reliability engineers often want to work with systems with parallel and serial elements and to estimate their reliability‎. The inequality measures are widely applied in many sciences such as economic‎, ‎social sciences and other areas‎. ‎In this paper‎, ‎we investigate relations between a mean life time of system comprising of $n$ identical and independents having parallel or series of mixture in form of the some measures of income inequality‎. ‎The Gini index and generalized Gini index are two important indicators for measuring dispersion‎. ‎It is natural to try to relate Gini indices to mean life time of system‎. ‎We will obtain an upper bound for mean residual life of the parallel system from some inequality indices‎.

Keywords