New Lower Bounds for the Vehicle Routing Problem with Simultaneous Pickup and Delivery

Abstract. This work deals with the Vehicle Routing Problem with Simultaneous Pickup and Delivery. We propose undirected and directed two-commodity flow formulations, which are based on the one developed by Baldacci, Hadjiconstantinou and Mingozzi for the Capacitated Vehicle Routing Problem. These new formulations are theoretically compared with the one-commodity flow formulation proposed by Dell’Amico, Righini and Salani. The three formulations were tested within a branch-andcut scheme and their practical performance was measured in well-known benchmark problems. The undirected two-commodity flow formulation obtained consistently better results. Several optimal solutions to open problems with up to 100 customers and new improved lower bounds for instances with up to 200 customers were found.

• Type: Conference
• Year: 2010
• Where: WEA
• Authors: Anand Subramanian, Eduardo Uchoa, Luiz Satoru Ochi
• Keywords: Algorithms, Two-commodity flow Formulation, Undirected, Vehicle Routing Problem, WEA 2010