ABSTRACT
Over the last century, continuing increase in energy consumption and emissions of greenhouse gases, which mainly stems from industrial activities, has brought about serious environmental problems such as global warming and climate change. Consequently, global awareness on environmental issues has increased rapidly in recent years, making the reverse logistics activities more important. The activities in the context of reverse logistics cover recycling and reusing operations that require bidirectional flow of goods. As a result, the design of the transportation systems requiring both pickup and delivery services becomes crucial for companies to minimize transportation costs.
