Belgin, ÖnderKaraoğlan, İsmailAltıparmak, Fulya2020-03-262020-03-262015https://hdl.handle.net/20.500.12395/3287145th International Conference on Computers and Industrial Engineering, CIE 2015 -- 28 October 2015 through 30 October 2015 -- 118692As one of the most important areas of logistics management, vehicle routing is well-known combinatorial optimization problem. In this study a variant of vehicle routing problem called twoechelon vehicle routing problem with simultaneous pickup and delivery (2E-VRPSPD) is considered. The 2E-VRPSPD performs the pickup and delivery activities simultaneously by the same vehicles through depot to satellites in the first echelon and from satellites to customers in the second echelon. In this study, we propose a node-based mathematical model for the problem and three valid inequalities adapted from the literature to strengthen the model. Computational results are provided to demonstrate the effectiveness of the proposed mathematical model.eninfo:eu-repo/semantics/closedAccessSimultaneous pickup and deliveryTwo-Echelon vehicle routingConference ObjectN/A