ABSTRACT
Good progress has been made on some integrated routing problems insofar as being able to jointly model and solve problems at two different levels of planning. This chapter presents two formulations for the location-routing problem, both of which are based on different types of flow. The first one is an exponential-sized formulation and is based on the flow of vehicles. The second one is a compact formulation that is polynomial in the number of constraints and describes the flow of two commodities on the network. Planning models should ideally incorporate as many decisions as is practically possible to exploit the interdependencies and be solved to arrive at an overall optimum design for the distribution network as a whole. The literature on the location-routing problem is rich. The production-routing problem is relatively new and the research on the problem is yet to reach maturity.
