A multi-commodity, multi-modal network flow model for logistics management.

摘要

This research attempts to formulate and solve a very complex problem in logistics management. The problem to be addressed is a large-scale multi-commodity, multi-modal network flow problem with time windows. Due to the nature of this problem, the size of the optimization model which results from its formulation grows extremely rapidly as the number of modes and/or commodities increase. Development of an innovative formulation for this problem and an efficient solution algorithm which lends itself to implementation in a decision support system are major theoretical and algorithmic contributions to the state-of-the-art in network modeling and logistics management. This research presents a formulation of the problem based on the concept of a time-space network. Two heuristic algorithms are developed. One is a heuristic which exploits an inherent network structure of the problem with a set of side constraints and the other is an interactive fix-and-run heuristic. The findings of the model implementation and a wide range of sensitivity analyses are also described using an artificially generated data set in the context of disaster relief operations.