While various forms of stochastic domination (including stochastic, hazard rate or likelihood ratio ordering) of one random variable over another have proven useful in making comparisons between systems, they share a common limitation. These modes of comparing systems induce only a partial ordering on the class of systems of interest, leaving some pairs of systems non-comparable. Comparisons via stochastic precedence (as defined in [1]) do not suffer from this limitation. In this paper, we describe how stochastic precedence may be used as a metric in comparing arbitrary systems whose components are assumed to be independent and identically distributed with common distribution F. An explicit computational formula is displayed for the relevant probability P(T₁≤T₂), where T₁ and T₂ are system lifetimes. A necessary and sufficient condition depending solely on system signatures is given for stochastic precedence between system lifetimes. Examples are given that illustrate the fact that systems whose lifetimes are not comparable by stochastic, hazard rate or likelihood ratio ordering may be definitively compared via stochastic precedence. In the final section, we focus on comparisons between systems whose signatures are symmetric.