In this paper we present a componentwise delay measure for estimating and improving the expected delays experienced by customers in a multi-component inventory/ assembly system. We show that this measure is easily computed. Further, in an environment where the performance of each of the item delays could be improved with investment, we present a solution that aims to minimize this measure and, in effect, minimizes the average waiting time experienced by customers. © 2002 Wiley Periodicals, Inc. Naval Research Logistics 50: 184–194, 2003.