Abstract
In this paper we consider the problem of minimizing the waste of textile material in a Portuguese home textile manufacturing company. The company has a vertical structure covering the different production stages of the home textile, from weaving until the finished products. Production planning comprises different decisions: the definition of the widths and lengths of the fabric rolls to be produced, the number of fabric rolls to be used from stock or purchased and the definition of the cutting patterns to be applied to each width of the fabric roll, so that the waste is minimized. We propose a MIP model, solved by a column generation method, to tackle the problem.

Abstract
Internet sales channels, especially e-brokers that compare prices in the market, have a major impact on car rentals. As costs are heavily correlated with unoccupied fleet, occupation considerations should be integrated with swift responses to the market prices. This work was developed alongside Guerin, a Portuguese car rental, to build a tool that quickly updates prices on e-brokers websites to increase total value. This paper describes the specificities of the problem and their implication on the solution, and presents an adaptative heuristic to update prices and the system’s architecture. © 2015, Springer International Publishing Switzerland.

Abstract
Cutting and packing problems generally address the cutting or packing of smaller items into a larger container object. Usually, the main methodologies used in the Circular Open Dimension Problem (CODP) are nonlinear programming methods or methods that combine different heuristics. The aim of this project is at devising and using an agent-based simulation approach to determine the length of the open rectangle in CODP; more specifically, we look into the Circular two-dimension Open Dimension Problem. Agents (circles, which can have different dimensions) were given a set of simple rules that allow them to be placed in the world (i.e. an open rectangle). These rules are inferred from the formal CODP formulation and from the behavior defined in the agents.

Abstract
There is growing evidence that internationalization of small and medium enterprises (SMEs) has become a priority to gain competitive advantage. However, SMEs still face major challenges and obstacles during these processes. This paper proposes a model of collaborative networks for internationalization processes of SMEs, mediated by industrial enterprise associations (IEAs), in order to improve decision-making processes. First, a systematic literature review (SLR) was performed to study the impact that networks and collaboration have in the decision-making process of internationalization. Then, the model was developed using adequate information and knowledge management tools. Finally, to understand the relevance of the proposed model, data were gathered through interviews to key persons in companies of the IT/electronics and textile industries. Results showed that collaborative networks can represent an important facilitator in the internationalization of SMEs and that IEAs can have a fundamental role for promoting collaboration in this domain, between associated SMEs.

Abstract
In this paper we introduce the dial-a-ride problem with split requests and profits (DARPSRP). Users place transportation requests, specifying a pickup location, a delivery location, and a time window for either of the two. Based on maximum user ride time considerations, the second time window is generated. A given fleet of vehicles, each with a certain capacity, is available to serve these requests, and maximum route duration constraints have to be respected. Each request is associated with a revenue and the objective is to maximize the total profit, that is, the total revenue minus the total costs. Transportation requests involving several persons may be split if it is beneficial to do so. We formulate the DARPSRP as a mixed-integer program using position variables and in terms of a path-based formulation. For the solution of the latter, we design a branch-and-price algorithm. The largest instance solved to optimality, when applied to available instances from the literature, has 40 requests; when applied to newly generated instances, the largest instance solved to optimality consists of 24 requests. To solve larger instances a variable neighborhood search algorithm is developed. We investigate the impact of request splitting under different geographical settings, assuming favorable settings for request splitting in terms of the number of people per request. The largest benefits from request splitting are obtained for problem settings exhibiting clustered customer locations.

Abstract
The term Dynamic Manufacturing Network (DMN) refers to a new collaborative business model that relies on real-time information sharing, synchronized planning and common business processes. DMNs are operational networks formed among autonomous and globally dispersed partners, and can be seen as the manufacturing industry application of the Virtual Enterprise (VE) concept. Despite their numerous practical benefits such as optimized processes and access to new and global markets, they are particularly vulnerable to disruptions. Any disruption in manufacturing or transportation of products may obviously result in failed orders, thus impacting the whole DMN reliability. Instead of developing stochastic models to deal with uncertainty, as it is usually done, we have rather integrated the concept of flexibility into the tactical and operational planning of such networks. We therefore propose in this work, a multi-objective optimization model that simultaneously maximizes reactive flexibility measures while minimizing total operating costs.