the vehicle routing problem with simultaneous pickup and delivery (vrpspd) is a well-known combinatorial optimization problem which addresses provided service to a set of customers using a homogeneous fleet of capacitated vehicles. the objective is to minimize the distance traveled. the vrpspd is an np-hard combinatorial optimization problem. therefore, practical large-scale instances of vrpspd...

In real-world express systems, couriers need to satisfy not only the delivery demands but also pick-up of customers. Delivery and pickup tasks are usually mixed together within integrated routing plans. Such a problem can be abstracted formulated as Vehicle Routing Problem with Mixed Pickup (VRPMDP), which is an NP-hard combinatorial optimization problem. To solve VRPMDP, there three major chal...

The transport requirements in modern society are becoming more and more important. Thus, offered transport services need to be more and more advanced and better designed to meet users demands. Important cost factors of many goods are transport costs. Therefore, a reduction of costs, a better adjustment of strategies to the demand as well as a better planning and scheduling of available resource...

One important problem in transportation and logistics systems is the Multiple Vehicle Pickup and Delivery Problem with Time Windows (MV-PDPTW). The problem deals with a number of pickup and delivery (P&D) requests that should be served by a fleet of vehicles. A delivery location must be served after its corresponding pickup location. The vehicle’s journey should start and end at a central depot...

The pickup and delivery problem with time windows is the problem of serving a number of transportation requests using a limited amount of vehicles. Each request involves moving a number of goods from a pickup location to a delivery location. Our task is to construct routes that visit all locations such that corresponding pickups and deliveries are placed on the same route and such that a pickup...

The pickup and delivery problem with time windows is the problem of serving a number of transportationrequests using a limited amount of vehicles. Each request involves moving a number of goods from apickup location to a delivery location. Our task is to construct routes that visit all locations such thatcorresponding pickups and deliveries are placed on the same route and such that...

In this paper, we consider vehicle routing problems with backhauls and time windows (VRPBTW). Different backhaul variants are studied, namely clustered backhauls (CB), mixed linehauls and backhauls, and variants with simultaneous delivery and pickup and with divisible delivery and pickup. Three dimensional loading constraints are assumed. A two-phase approach following the principle packing fir...

Continuous growth in air cargo deliveries and increasing competition is necessitating freight forwarders to develop innovative solutions to improve performance and reduce costs. This study considers a freight forwarder's operational implementation of alternative access airport policy in a multi-airport region for air cargo transportation. Given a set of heterogeneous air cargo customers, the fo...