The Facts on the Ground : Evaluating Humanitarian Fleet Management Policies Using Simulation

In humanitarian fleet management, the performance of purchase, assignment, and sales decisions is determined by dynamic interactions between the fleet composition (vehicles that were acquired at different times and have different residual values), the time-varying and uncertain demands on the fleet, and the depreciation of the vehicles as they are exploited. When all of these factors are taken into account, optimal decisions become analytically intractable. We pro-pose to evaluate purchase, assignment, and sales policies in a realistic simulation environment that directly models heterogeneous vehicle attributes and tracks their evolution over time. Using data from a large international humanitarian organization (LIHO), the simulator can identify the rationale behind seemingly ad-hoc decisions by field managers at LIHO. For instance, by selling vehicles later than LIHO recommends, managers are actually reducing their costs; similarly, managers decline to coordinate vehicles between mission types because the merits of "sharing" in this way turn out to be marginal at best