Modeling cost-delivery trade-offs for distribution logistics by a generalized PVRP model

This article provides a mathematical model to support management in making decisions about cost-delivery trade-offs in the case of cost-delivery flexibilities in distribution logistics. The optimization problem can be modeled as a bi-objective periodic vehicle routing problem, which is known as NP-hard. In the periodic vehicle routing problem considered in this study, no delivery patterns are pre-defined, instead the patterns are the result of the optimization process of the model. In addition, delivery time flexibilities are incorporated in the model. A heuristic solution method for realistic problem sizes is based on the tabu search procedure, and a real case study illustrates the applicability of the solution concept.