Facility Location Alternatives between Expected and Worst Case Time Performance in Humanitarian Relief Logistics

Abstract

In the field of humanitarian logistics, facility and stock positioning are receiving more research attention than they had in the past because of the steep increase in natural disasters around the world. In such studies, objective functions are among the most important criteria used to classify facility location models. A review of related literature has determined that most optimization models formulate their objective functions from numerous different aspects, and that the two most popular objective functions are cost and time minimization. Among the time performance aspects, models designated as type (A) generally refer to those designed to minimize the total expected response time between demand points and facilities over the whole logistics system. However, type (B), consisting of fewer models, attempts to minimize the maximum response time or distance between demand points and facilities rather than attempting to address average system performance. The goal of this research is to propose two facility location models for humanitarian relief logistics by focusing on response time objective aspects, and to analyze the structure of those two models by conducting extensive numerical experiments. Illustrative examples are provided to show how the proposed models can be used to optimize stock facility locations in order to address relief supply chain problems. Furthermore, comparisons of the performance and solution for the two models are well described from several perspectives related to emergency logistics.