This thesis main objective is to address the location-routing problem (LRP) which intends to tackle, using an integrated approach, two highly related logistics activities: the location of facilities and the distribution of materials. The LRP, namely its mathematical formulation, has been studied in the literature, and several approaches have emerged, corresponding to different real-world scenarios. Therefore, it is important to identify and group the different LRP variants, in order to segment current research and foster future studies. After presenting a review and a taxonomy of location-routing models, the following research focuses on solving some of its variants. Thus, a study of two of the most basic LRPs (capacitated problems with demand either on the nodes or on the arcs) is performed, and new approaches are presented. Afterwards, the location-routing of semi-obnoxious facilities is addressed. These are facilities that, although providing useful and indispensible services, given their nature, bring about an undesirable effect to adjacent communities. Consequently, to the usual objectives when considering their location (cost minimization), new ones must be added that are able to reflect concerns regarding the quality of life of the communities impacted by the outcome of these decisions. The location-routing of semi-obnoxious facilities therefore requires to be analysed using multi-objective approaches, which can be of two types: non-interactive or interactive. Both are discussed and new methods proposed in this thesis; the proposed interactive method is suitable to other multi-objective mixed integer programming problems. Finally, a newly developed decision-support tool to address the LRP is presented (being the adopted methodology discussed, and its main functionalities shown). This tool has great concerns regarding the user interface, as it is directed at decision makers who typically don't have specific knowledge of the underlying models of this type of problems.

This paper proposes a hybrid genetic algorithm (GA) to solve the capacitated location-routing problem. The proposed algorithm follows the standard GA framework using local search procedures in the mutation phase. Computational evaluation was carried out on three sets of benchmark instances from the literature. Results show that, although relatively simple, the proposed algorithm is effective, providing competitive results for benchmark instances within reasonable computing time.

Recent years have shown an increasing use of lean manufacturing (LM) principles and tools in several industrial sectors. Already a well-established management philosophy, it has shown numerous successful applications even outside production environments. This work presents the application of some LM tools, and the corresponding shift in philosophy, in two Portuguese companies of the food and beverage industries. Main implementation issues are presented and discussed; followed by the results obtained from the application of LM tools in the production system of these companies. Significant gains are obtained in both companies and, more importantly, it instills a continuous improvement culture and increases production flexibility while reducing lead times.

This paper considers the rural road network upgrading problem, using a multi-objective optimization model, to support decision-makers in the choice of roads to upgrade in the hilly regions of Nepal. The model considers two objectives: minimization of user operation costs and maximization of population covered. The problem was solved for a real-world rural road network in the Gorkha district of Nepal. For this case, all non-dominated solutions were obtained and the ones providing more interesting trade-offs were analysed. The model was found suitable for the case under study, and possibly, easily extendable to rural areas of other developing countries.

Location-routing is a branch of locational analysis that takes into account distribution aspects. The location-arc routing problem (LARP) considers scenarios where the demand is on the edges rather than being on the nodes of a network (usually a road network is assumed). Examples of such scenarios include locating facilities for postal delivery, garbage collection, road maintenance, winter gritting and street sweeping. This paper presents some heuristic approaches to tackle the LARP, as well as some proposals for benchmark instances (and corresponding results). New constructive and improvement methods are presented and used within different metaheuristic frameworks. Test instances were obtained from the capacitated arc routing problem (CARP) literature and adapted to address the LARP.

Location-routing is a branch of locational analysis that takes into account distribution aspects. This paper proposes a taxonomy, with two levels, for location-routing problems. The first level focuses on the structural characteristics of the problems. The second level branches into the different algorithmic approaches and objective perspectives. An introduction to the previously defined problems is presented, categorising the papers in the literature (a total of 149 references) according to the proposed classification. Moreover, an overview of the most significant aspects of the different solution methods and main objectives, with special emphasis on multi-objective approaches, is provided. Some data providing a better insight into the publication progress are also included. Finally, several promising research directions are identified.

This paper introduces a new physical simulation game framework, which can be used in a classroom environment (for both students and professionals) to help demonstrate the applicability as well as the potential advantages of lean production. The game provides a hands-on experience, focusing on experimental learning, and thus enabling students/trainees to get a deeper understanding of the lean principles. The use of simulation games is not, however, restricted to teaching, as it can also be used to test real-life implementations of production systems. By using the proposed game framework, professionals may have a cheap alternative to expensive simulation software. The game starts out by creating an unbalanced system. Throughout the iterations of the game, lean principles are introduced and implemented in the system, thus allowing students/trainees to understand how lean production can be implemented in organizations. The game elements, design of the initial system, as well as subsequent iterations, are presented and briefly discussed.

In this paper we present a decision-support tool (DST) that implements a capacitated location-routing problem (CLRP) with two levels (depots and customers) and a capacitated and homogeneous vehicle fleet. It allows the exploration of the solution finding process in a way easily understandable by the user, and enables access to online geographic data through web map servers (WMS). This tool was developed for Windows platforms having an architecture that easily allows the integration of new functionality.