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...

this paper considers the multi-depot vehicle routing problem with time window in which each vehicle starts from a depot and there is no need to return to its primary depot after serving customers. the mathematical model which is developed by new approach aims to minimizing the transportation cost including the travelled distance, the latest and the earliest arrival time penalties. furthermore, ...

increasing of the distribution efficiency is one of the most objectives of an integrated logistic system developed as a new management philosophy in the past few decades. the problem is examind in two parts: facilities location problem (flp) for long policies and vehicle routing problem (vrp) to meet the customer demand. these two components can be solved separately; however, this solution may ...

Using Greedy Clustering Method to Solve Capacitated Location-Routing Problem with Fuzzy Demands Abstract In this paper, the capacitated location routing problem with fuzzy demands (CLRP_FD) is considered. In CLRP_FD, facility location problem (FLP) and vehicle routing problem (VRP) are observed simultaneously. Indeed the vehicles and the depots have a predefined capacity to serve the customerst...

Regarding the development of distribution systems in the recent decades, fuel consumption of trucks has increased noticeably, which has a huge impact on greenhouse gas emissions. For this reason, the reduction of fuel consumption has been one of the most important research areas in the last decades. The aim of this paper is to propose a robust mathematical model for a variant of a vehicle routi...

One of the most important extensions of the capacitated vehicle routing problem (CVRP) is the vehicle routing problem with simultaneous pickup and delivery (VRPSPD) where customers require simultaneous delivery and pick-up service. In this paper, we propose an effective ant colony optimization (EACO) which includes insert, swap and 2-Opt moves for solving VRPSPD that is different with common an...

the capacitated location-routing problem (clrp) is a new research area in logistics and distribution management. this problem combines two difficult problems: the facility location problem (flp) and vehicle routing problem (vrp). the goal of the clrp is to open a subset of depots, assign the customers into open facilities, and then design vehicle tours in order to minimize the total cost. the t...

this paper discusses the multi-depot vehicle routing problem of heterogeneous fleet of vehicles with time windows for perishable commodities. the objective of the problem is to minimize the total time required for servicing all customers that is equivalent to the total cost. commodities are delivered to the customers with defined time windows by a fleet of heterogeneous vehicles, which have lim...