This paper presents a column generation algorithm for the Vehicle Routing Problem with Time Windows (VRPTW). Traditionally, column generation models of the VRPTW have consisted of a Set Partitioning master problem with each column representing a route, i.e., a resource feasible path starting and ending at the depot. Elementary routes (no customer visited more than once) have shown superior resu...

This paper addresses a fuel-constrained, autonomous vehicle path planning problem in the presence of multiple refueling stations. We are given a set of targets, a set of refueling stations, and a depot where m vehicles are stationed. The vehicles are allowed to refuel at any refueling station, and the objective of the problem is to determine a route for each vehicle starting and terminating at ...

We address in this paper a distribution real case problem facing the fuel supplying companies. The cost of acquiring vehicles is often more significant than the routing cost. The goal is to minimise the number of required vehicles. We deal with a vehicle routing problem with double time windows for the depot and multiple use of vehicles (VRPDM). There is a single depot with double time windows,...

This paper introduces the Pyramidal Capacitated Vehicle Routing Problem (PCVRP) as a restricted version of the Capacitated Vehicle Routing Problem (CVRP). In the PCVRP each route is required to be pyramidal in a sense generalized from the Pyramidal Traveling Salesman Problem (PTSP). A pyramidal route is defined as a route on which the vehicle first visits customers in increasing order of custom...

N P-hard problem as a total distance minimization problem. Natural extension of the notorious traveling salesperson problem (TSP) with… Delivery vehicles (homogeneous or heterogeneous fleet) have a limited capacity. One or more nodes in the graph (single depot vs. multi-depots) are designated as origins of routes. Each route should emanate from such an origin node. The rest of the nodes are ide...

The Vehicle Routing Problem (VRP) involves the design of a set of minimum cost vehicle routes, originating and terminating at a central depot, for a fleet of vehicles that services a set of customers with known demands. This study contains some information about Logistics and Supply Chain Management. In the second part Distribution Management, which is a more related subject with Vehicle Routin...

The Vehicle Routing Problem with Time Windows (VRPTW) consists of constructing least cost routes from a depot to a set of geographically scattered service points and back to the depot, satisfying service time interval and capacity constraints. A Variable Neighbourhood Search algorithm with Compound Neighbourhoods is proposed to solve VRPTW in this paper. A number of independent neighbourhood op...

Several challenges are associated with current vaccine strategies, including repeated immunizations, poor patient compliance, and limited approved routes for delivery, which may hinder induction of protective immunity. Thus, there is a need for new vaccine adjuvants capable of multi-route administration and prolonged antigen release at the site of administration by providing a depot within tiss...

Vehicle Routing Problem (VRP) is a key element of many logistic systems which involve routing and scheduling of vehicles from a depot to a set of customers node. This is a combinatorial optimization problem with the objective to find an optimal set of routes used by a fleet of vehicles to serve a set of customers It is required that these vehicles return to the depot after s erving customers’ d...

The present work aims to support tactical and operational planning decisions of reverse logistics systems while considering economic, environmental and social objectives. In the literature, when addressing such systems economic aspects have been often used, while environmental concerns have emerged only recently. The social component is the one less studied and rarely the combination of the thr...