For and a supermodular set function , define the polymatroid . The authors develop a bound for the probability , where is a random m-vector. In particular they show that if , are independent and identically distributed nonnegative random variables with new better than used (NBU) distribution function, then , where . á(NBU) distribution function, then >F100<P >F003<A>F004<X >F003<. >F109<p>F000<(>F100<màAF02,àAF12f >F000<)>F003<S e >F100<P >F003<A>F100<X >F003<e >F100<f >F000<(>F100 H08W08<M>$-55<àI>F000 H08W09.5J102<ˆàR>$29 F100 H08W08< >F000<)>F003<S>F100<àAF02, >F000<where >F100 H08W08<M>$-55<àI>F000 H08W09.5J102<ˆàR>$29 F100 H08W08< >F000<= argàAF12max>F003<A>F100<f >F000<(>F100<A>F000<):àAF12>F100<A >F001<Y >F100<M >F003<S>F100<. The authors apply this result to transportation problems with random supply and/or demand. Suppose they have a set of k supply nodes with a random supply and a set of n demand nodes with a random demand . Let be the probability that the random demand can be met by the random supply. If the demand and supply are mutually independent, are independent, and are independent and have NBU distribution function, then , where , and takes the value one if node can supply the demand node and zero otherwise and .