Atık pillerin tersine lojistik ağ tasarımı ve Türkiye uygulaması

Reverse logistics has received increasing attention in the last decade. This is mainly due to the environmental concerns, forcing legislations, and potential economic benefits. Ever increasing amount of waste batteries which are classified as hazardous waste poses a significant environmental problem; thus it requires an effective management. In this thesis, we develop a mixed-integer linear programming model (MILP) to design reverse logistics network for waste batteries and implemented the model to the Turkey case. The proposed model has various realistic features compared to existing models; it is a multi-period optimization model that considers various battery-types, different capacity options, capacity expansion of facilities, sale prices of recycled materials, variable operational cost, construction cost, and existing infrastructure of the facilities in the network. There are two disposal options for waste batteries: recycling and landfill. Using the developed optimization, the policy makers responsible for the design and operation of the reverse network of waste batteries can decide on the network configuration, while maximizing the profit. Uncertainty in the return of waste batteries is a major issue in the reverse logistics network design. As the network design requires high investment costs, the uncertainty has to be taken into account. In addition to the deterministic network optimization model, a stochastic programming approach is presented by adding scenarios to consider the uncertain amounts of waste battery returns explicitly. All models are programmed and implemented in GAMS (General Algebraic Modeling System) optimization package and solved using the CPLEX solver. Finally, we conduct sensitivity analyses to determine which parameters are critical for the network structure and to analyze the impact of variations in the critical parameters.