The notion of a hybrid fuel cell vehicle is promising in the sense that size and cost reductions for the fuel cell unit can be achieved by offloading much of the peak power requirements to an auxiliary energy storage device (either a battery or super-capacitor). However, to maximize the efficacy of such a system, a power management coordination unit (or controller) will need to be designed. Additionally, the design of this controller and its ability to meet drive cycle requirements will be dramatically influenced by earlier decisions concerning the size of the fuel cell and energy storage devices. Thus, the objective of this work is to develop a scheme that simultaneously designs the controller while sizing the fuel cell and energy storage units. Such an approach, in which system design decisions are driven by the capabilities of the closed-loop system, represents a paradigm shift in hybrid vehicle design.