Collection center location in reverse logistics networks

In this thesis, we study collection center location problem for municipalities within reverse logistics networks. The aim of the problem is to determine the locations and the capacities of the collection centers through the planning horizon. For each time period, the decisions to be made include the location and the capacities of the collection centers, amounts of products to send from each generation point to each collection center and the amounts of products to send from each collection center to each firm. The problem has three objectives. The first one is to minimize total costs, second one is to distribute products fairly among different firms, and the third is to provide steady flow of products to each firm along the planning horizon. The problem is modeled as a multi-objective mixed integer programming formulation. An implementation of the problem is proposed for Ankara municipality within the context of waste of electrical and electronic equipment collection. Sensitivity analyses are presented to observe the effect of changes in the problem parameters on optimal solutions. The analyses include changes in the set-up costs and capacities, changes in the amount of returns and growth rate, and changes in the planning horizon. In addition, the solution potential of the model and the benefits of using a multi-period model as opposed to a static one are investigated.