In pickup and delivery problems (PDPs), vehicles pickup and deliver a set of items under various constraints. We address the PDP with Transfers (PDP-T), in which vehicles plan to transfer items between one another to form more efficient schedules. We introduce the Very Large Neighborhood Search with Transfers (VLNS-T) algorithm to form schedules for the PDP-T. Our approach allows multiple trans...

The vehicle routing with pickups and deliveries (VRPD) problem is de6ned over a graph G=(V; E). Some vertices in G represent delivery customers who expect deliveries from a depot, and other vertices in G represent pickup customers who have available supply to be picked up and transported to a depot. The objective is to 6nd a minimum length tour for a capacitated vehicle, which starts at a depot...

In this paper we consider a rich vehicle routing problem where transportation requests are characterised by multiple pickup and delivery locations. The problem is a combined load acceptance and generalised vehicle routing problem incorporating a diversity of practical complexities. Among those are time window restrictions, a heterogeneous vehicle fleet with different travel times, travel costs ...

In the pickup and delivery problem with time windows (PDPTW), vehicle routes must be designed to satisfy a set of transportation requests, each involving a pickup and a delivery location, under capacity, time window, and precedence constraints. This paper introduces a new branch-and-cut-and-price algorithm in which lower bounds are computed by solving through column generation the linear progra...

Over time, large scale pickup and delivery providers acquire considerable amounts of data on customer orders, including order times, amount and configurations of freight, as well as the locations for pickup and delivery. If their fleet is equipped with tracking devices, additional GPS data can be provided and actual travel routes can be saved for later evaluation. In this paper, we present two ...

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 ...

In the Traveling Salesman Problem with Pickup and Delivery (TSPPD) a single vehicle must serve a set of customer requests, each defined by an origin location where a load must be picked up, and a destination location where the load must be delivered. The problem consists of determining a shortest Hamiltonian cycle through all locations while ensuring that the pickup of each request is performed...

This paper studies the multi-objective pickup and delivery problem with time windows (PDPTW), in which a fleet of homogeneous vehicles with the same capacities located in a depot serve a collection of given transportation requests. Each request is composed of a pickup location, a delivery location and a given load. The PDPTW is to determine a vehicle scheduling strategy with the objectives of m...

This thesis shows how both the PDPTW (Pickup and Delivery Problem with Time Windows) and a variant where travel times are non-deterministic (Pickup and Delivery Problem with Disturbances), can be solved by an approximation algorithm that uses Linear Programming with column generation. In the pricing problem – which is solved by Simulated Annealing – an Evolutionary Algorithm helps to execute be...