Seminar


Date : Oct. 12, 2023, 2 p.m. - Room :Espace Fauriel - Salle 514

Solving the Location-Routing Problem with Loading Constraints


Thiago Alves de Queiroz - Federal University of Catalão - Brazil

A hybrid heuristic is proposed to solve a location-routing problem with two-dimensional loading constraints. This problem appears in military situations and natural disasters in such a way that decisions are taken in a short time horizon. The proposed heuristic combines the simulated annealing method and the artificial algae algorithm. Simulated annealing is used to handle the location- routing problem, while the artificial algae algorithm is used to determine the sequence in which the items will be packed. Therefore, we apply the Skyline technique to find a feasible packing of such items onto the vehicle’s rectangular surface. As there is no other work in the literature handling the location-routing problem with two-dimensional loading constraints that we can compare the results, we evaluate the heuristic performance on its subproblems: the location-routing problem and the vehicle routing problem with two-dimensional loading constraints. Although the heuristic is not designed for these subproblems, it still obtains competitive results, with an average relative difference of 1.26% and equal or better solutions for more than 90 instances. Regarding the problem under study, the heuristic obtains solutions close to an estimated lower bound for instances having more items per customer.

Short Bio: Thiago is Associate Professor at the Institute of Mathematics and Technology (IMTech) of the Federal University of Catalão (UFCAT, Brazil) and since 2020 is the Director of Research at UFCAT. He received a B.Sc. in Computer Science from the Federal University of Goiás in 2007. In February 2007, he was a junior research fellow at the Investigation Center of Computational Methods, in Santa Fé, Argentina, developing numerical methods for non-linear dynamic problems in solid mechanics. In 2008, he received an M.Sc. in Mechanical Engineering from the Federal University of Uberlândia, Minas Gerais, Brazil. From 2008 to 2010, he worked with the Combinatorial Optimization Group at the Institute of Computing, University of Campinas, Campinas, São Paulo, Brazil, on exact and heuristic methods for cutting and packing problems for his doctorate. In 2013-2014, he was a postdoctoral fellow at the Institute of Computing, University of Campinas, Campinas, São Paulo, Brazil. In 2014, he was a visiting researcher at the Department of Management and Industrial Engineering, Faculty of Engineering of the University of Porto, Portugal, and at the Combinatorial Optimisation and Decision Support Research Group, Kaho Sint-Lieven University in Gent, Belgium. In 2016-2017, he was a postdoctoral fellow at the Institute of Mathematics and Computer Sciences, University of São Paulo, São Carlos, São Paulo, Brazil. In 2019, he was a postdoctoral fellow at the Department of Sciences and Methods for Engineering, University of Modena and Reggio Emilia, Reggio Emilia, Italy. In 2021, 2022, and 2023, he was a visiting professor at the same department. His main research interests include developing intelligent exact and heuristic algorithms for practical optimization problems such as cutting and packing, scheduling, vehicle routing, and their integrations (vehicle routing with packing, location-routing, etc.).