No abstract

É uma tarefa difícil expressar em palavras o quão importante são todos aqueles que colaboraram e me apoiaram, direta e/ou indiretamente, para desenvolvimento deste trabalho. Mas vou tentar! Vou começar por agradecer àqueles que são de suma importância para mim, não só por me conceder a vida, mas também pelos constantes ensinamentos de amor, de confiança, de companheirismo, enfim por tudo que sou e pelo apoio incondicional em toda minha trajetória, assim, primeiramente gostaria de agradecer aos meus pais, Denivaldo Baldo e Francisca Pinheiro da Silva Baldo. À minha irmã, Thaísa Aparecida Baldo, que juntamente com meus pais sempre esteve ao meu lado. Resumindo, meus primeiros agradecimentos vão à minha família por todo apoio, compreensão, carinho, atenção, conselho e incentivo durante toda a minha vida e principalmente nestes dois últimos anos aqui em São Carlos. A Deus por estar sempre ao meu lado. Ao meu orientador Marcos Nereu Arenales pela paciência, conselhos e constante apoio. À professora Maristela Santos pelo tempo dispendido de atenção, conselho, incentivo, bronca, amizade, enfim por tudo, pois com certeza é uma grande colaboradora deste trabalho. Aos companheiros do LOT (laboratório de otimização do ICMC

This research proposes new approaches to deal with the production planning and scheduling problem in brewery facilities. Two real situations found in factories are addressed, which differ by considering (or not) the setup operations in tanks that provide liquid for bottling lines. Depending on the technology involved in the production process, the number of tank swaps is relevant (Case A) or it can be neglected (Case B). For both scenarios, new MIP (Mixed Integer Programming) formulations and heuristic solution methods based on these formulations are proposed. In order to evaluate the approach for Case A, we compare the results of a previous study with the results obtained in this paper. For the solution methods and the result analysis of Case B, we propose adaptations of Case A approaches yielding an alternative MIP formulation to represent it. Therefore, the main contributions of this article are twofold: (i) to propose alternative MIP models and solution methods for the problem in Case A, providing better results than previously reported, and (ii) to propose new MIP models and solution methods for Case B, analyzing and comparing the results and benefits for Case B considering the technology investment required.

This study deals with the multistage lot-sizing and scheduling problem in breweries.The brewing process can be divided into two main stages: preparation and filling of the liquid. The first stage occurs most of the time in fermentation and maturation tanks. The second stage occurs in the filling lines and it can start as soon as the liquid gets ready. The preparation time of the liquid takes several days, while in the carbonated beverage industries this time is at most a few hours. The purpose of this study is to obtain feasible production plans aimed at optimizing the decisions involved in these processes. Visits to brewery industries in Brazil and Portugal were held to a greater familiarity of the production process and data were collected. Mixed integer programming models have been developed to represent the problem, based on approaches for the CSLP (The Continuous Setup Lot-Sizing Problem), GLSP (General Lot Sizing and Scheduling Problem), SPL (Simple Plant Location Problem) and ATSP (Asymmetric Travelling Salesman Problem). The results show that the models are consistent and adequately represent the problem; however, they are difficult to be solved at optimality. This motivated the development of MIP-heuristic procedures, as well as a meta-heuristic GRASP (Greedy Randomized Adaptive Search Procedure). The obtained solutions by the heuristics are of good quality, when compared to the best lower bound found by solving the mathematical models. The tests were conducted using generated instances based on real data.