This paper proposes a tabu search algorithm for the two-echelon vehicle routing problem with time windows and simultaneous pickup delivery (2E-VRPTWSPD), which is new variant of problem. 2E-VRPTWSPD involves three stages routing: (1) first-echelon vehicles start from depot to deliver cargoes satellites; (2) second-echelon satellites serve customers within in simultaneously manner finally return...

The vehicle routing problem with simultaneous pickup and delivery (VRPSDP) is a common transportation problem where a fleet of vehicles deliver goods from the depot to line haul customers and pick up goods from backhaul customers to the depot. This problem variation allows vehicles to make the delivery and pickup operations on same time by visiting all clients once with the aim of minimization ...

In this paper, we introduce a new variant of Location-Routing Problem (LRP), namely the LRP with simultaneous pickup and delivery (LRPSPD). The LRPSPD is defined as finding locations of the depots and designing vehicle routes in such a way that pickup and delivery demand of each customer must be performed with same vehicle and the overall cost is minimized. We propose two polynomial-size mixed ...

This paper discusses the vehicle routing problem with simultaneous pickup and delivery (VRPSPD), in which both pickup and delivery tasks simultaneously occur at various customer locations. The objective is to design a set of minimum distance routes with the minimum number of vehicles satisfying all the customers. This paper proposes a heuristic algorithm consisting of a route construction proce...

The development of convergent technology makes the drone expected to become a commercial delivery method for terminal logistics distribution. Although industry has begun experiment with coordinated transportation drones and vehicles, some limited assumptions have been made reduce complexity synchronization. This paper studies mathematical formulations efficient solution methodologies multi-visi...

This work deals with the Vehicle Routing Problem with Simultaneous Pickup and Delivery (VRPSPD). 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...

We study a class of vehicle-routing problems (VRP) with simultaneous pickup and delivery (VRPSPD). In VRPSPDs, each customer may require a certain quantity of goods delivered from the depot and a quantity of goods to be picked up and returned to the depot. Besides the standard VRPSPD, we address (i) the VRPSPD with time limit (VRPSPDTL), which imposes a time limit on the routes of the transport...

The location routing problem with simultaneous pickup and delivery (LRPSPD) is a new variant of the location routing problem (LRP). The objective of LRPSPD is to minimize the total cost of a distribution system including vehicle traveling cost, depot opening cost, and vehicle fixed cost by locating the depots and determining the vehicle routes to simultaneously satisfy the pickup and the delive...