Comparisons of Mixed Systems Using Mean Vitality Function

The concept of system signature is widely used for comparing of mixed (coherent) systems. In practical situa-tions, it is usually impossible to compare mixed systems. To do this, some partial orders are considered in the literature. In this paper, we define a new concept of stochastic order for comparing mixed systems based on mean vitality function. We assume that component lifetimes of competing systems are independent and iden-tically distributed (iid) with a common distribution function. The obtained results are extended for comparing systems in which the component lifetimes are iid while the common component lifetime distributions are not identical. Some illustrative examples are also given