Analysis and integration of optimization models for logistic systems

The authors have developed some optimization models for the minimization of transportation and inventory costs on single links of logistic networks. Such models provide, for each link, the optimal frequencies at which trucks should travel and the optimal number of trucks needed for each frequency when only a discrete set of feasible frequencies is given. For this problem, simple EOQ-based models have been proposed in the literature. However, these models fail to yield feasible solutions, when only a given discrete set of feasible frequencies is available. The authors show on a set of problem instances that the present optimization model can provide solutions with costs lower than those obtained from EOQ-based models. Computational results are presented and discussed. The authors also show how models optimizing frequencies on a single link can be integrated in order to optimize shipment frequencies for simple networks.