A FURTHER NOTE ON THE FLEET DESIGN PROBLEM

ABSTRACT

In a recent paper, Jones and Zydiak [2] discuss the steady state fleet design problem, which has no natural initial distribution of vehicles. For this problem, they develop a new optimality criterion of minimizing annual equivalent cost per vehicle because the traditional optimally criterion of minimizing annual equivalent cost can lead to paradoxical results, as shown by example, when applied to the fleet design problem. In a subsequent note, Hartman [1] argues that this paradox is actually a result of a replacement convention that ignores opportunity costs. In this response, we demonstrate that paradoxical replacement behavior can occur with the traditional criterion even when opportunity costs are accounted for in the replacement analysis. We further conclude that the problems considered respectively by Jones and Zydiak [2] and Hartman [1] are fundamentally different in nature.