The multiple traveling salesman problem (MTSP) is a generalization of the famous traveling salesman problem (TSP), where more than one salesman is used in the solution. Although the MTSP is a typical kind of computationally complex combinatorial optimization problem, it can be extended to a wide variety of routing problems. This paper presents an efficient and evolutionary optimization algorith...

Vehicle Routing Problem with Time Windows (VRPTW) is a well known NP hard combinatorial scheduling optimization problem in which minimum number of routes have to be determined to serve all the customers within their specified time windows. Different analytic and heuristic approaches have been tried to solve such problems. The proposed hybrid algorithm uses ant colony system as well as random se...

The Capacitated Arc Routing Problem (CARP) is a difficult optimisation problem in vehicle routing with applications where a service must be provided by a set of vehicles on specified roads. A heuristic algorithm based on Tabu Search is proposed and tested on various sets of benchmark instances. The computational results show that the proposed algorithm produces high quality results within a rea...

This article deals with a complex vehicle routing problem that can be seen as a new extension of the basic vehicle routing problem. The proposed model is a multi-objective combinatorial optimization problem that considers three objectives and multiple periods, which models in a closer way the real distribution problems. The first objective is cost minimization, the second is balancing work leve...

This paper concerns the Split Delivery Vehicle Routing Problem (SDVRP). This problem is a relaxation of the Capacitated Vehicle Routing Problem (CVRP) since the customers’ demands are allowed to be split. We deal with the cases where the fleet is unlimited (SDVRP-UF) and limited (SDVRP-LF). In order to solve them, we implemented a multi-start Iterated Local Search (ILS) based heuristic that inc...

Combinatorial Testing (CT) is a sampling technique to generate test cases with a focus on the behavior of interaction system's components with their collaborators. Given its effectiveness to reveal faults, pairwise testing has often been chosen to perform the required sampling of test cases. The main concern for pairwise testing is to obtain the most optimal test sets (i.e. pairwise dictates th...

The Two-Echelon Routing Problem constitutes a class of combinatorial optimization problems with applications in many different fields such as city logistic planning, intermodal transportation, postal and parcel delivery distribution systems and so on. This thesis contains: a survey of the main contributions related to the two-echelon routing, focusing on the Two-Echelon Location Routing Problem...