Esteves, V. M. C., J. M. C. Sousa, C. A. Silva, A. P. B. Povoa, and M. I. Gomes. "
SCant-design: Closed loop supply chain design using ant colony optimization." In
2012 IEEE Congress on Evolutionary Computation (CEC). Brisbane, Australia, 2012.
AbstractThis paper proposes a new optimization methodology for supply chain design, using ant colony optimization. The objective of this methodology is to choose the facilities that will take part in a multi-product closed-loop supply chain, such as factories, warehouses and disassembly centers, in order to minimize the costs related to these facilities and those related to transportation costs, both in the forward and reverse chains. Considering that total production quantities for factories, expected cross-docking stocks for warehouses, and disassembly centers are determined by this methodology, it can be considered that it undertakes both strategic and tactical Supply Chain Management (SCM) problems at once. The developed algorithm, SCant-Design, is sufficiently general to solve any SCM configuration, with linear and nonlinear cost functions and constraints. The algorithm results were compared to a MILP approach for a particular case study and the obtained value for the cost function is very similar, although using less facilities.
Ramos, Tania Rodrigues Pereira, Maria Isabel Gomes, and Ana Paula Barbosa-póvoa. Solving a multi-product, multi-depot vehicle routing problem by a hybrid method In
Livro de actas do 15º congresso da APDIO, IO2011. Coimbra, Portugal, 2011.
AbstractThis paper is focused on the delimitation of service areas and on vehicle routes definition in recyclable waste collection systems with more than one depot. Three types of materials have to be collected in separated routes, so the problem is modelled as a multi-product, multi-depot vehicle routing problem. A hybrid method is developed where a MIP solver is embedded inside a heuristic framework. The effectiveness of this method is tested by comparing the results obtained for some test instances when solved only by an exact formulation. The hybrid method is then applied to a medium size problem based on a real recyclable waste collection system.
Baptista, Susana, Maria Isabel Gomes, and Ana Paula Barbosa-póvoa. "
A stochastic model for a multi-period multi-product closed loop supply chain." In
XVI Congresso da Associação Portuguesa de Investigação Operacional IO 2013, 27-37. Bragança, Portugal, 2013.
AbstractIn this work we propose a stochastic model for the design and planning of closed-loop supply chains.
Uncertainties in demand and return volumes are modelled together with uncertain transportation
costs. A two-stage stochastic programming is developed and a sensitivity analysis to the worst-case
probability is performed in order to test the solution robustness. Finally, in order to prove the
goodness of the stochastic approach, the value of the stochastic solution and the value of perfect
information are computed. An example based on a real case shows the model applicability.
Mota, Bruna, Maria Isabel Gomes, Ana Carvalho, and Ana Paula Barbosa-povoa. "
Supply chain design and planning accounting for the Triple Bottom Line." In
12th International Symposium on Process Systems Engineering and 25th European Symposium on Computer Aided Process Engineering. , 1842-1846. Copenhagen, Denmark : Elsevier, 2015.
AbstractIn this work, a multi-objective mixed integer linear programming (moMILP) model is presented for the design and planning of sustainable closed loop supply chains. It includes strategic decisions such as facility location, definition of transportation modes, technology selection and allocation, as well as tactical decisions. The model includes four objectives: 1) The economic pillar, measured through the net present value (NPV); 2) the environmental pillar, which includes Life Cycle Assessment (LCA), through the application of the ReCiPe methodology; 3 and 4) The social pillar measured using two socio-economic indicators applied by the European Union in its Sustainable Development Strategy. The applicability of the model is demonstrated through a representative supply chain case study. Results show that the different objectives influence the supply chain structure and translate in significantly different and conflicting decisions, showing the importance of such type of models to better understand the decisions implications on the different dimensions of sustainability.
Salema, Maria Isabel Gomes, A. P. Barbosa-Póvoa, and Augusto Q. Novais. "
Supply Chain Design and Planning with Product Return: An Optimization Approach." In
Production and Operations Management Society Conference, 1-11. Boston, USA, 2006.
AbstractThis paper addresses the design and planning of supply chains with product return. A graph approach is used as the modelling methodology. Commonly, the application of graph approaches to the design of supply chains, considers nodes as chain entities and arcs as connections between them. These assumptions are extended in the present work where products may also be associated with both nodes and arcs. A multi-product network formulation is obtained which is further generalised to consider the modelling of time, resulting in a dynamic multi-product network model with product return. This generalisation assumes that any node is a transformation point which allows inbound and outbound products to differ. Considering four different kinds of entities (factories, warehouses, sorting centres and customers), proper functions are defined for each one: production, postponement, usage and selection. An example, base on a Portuguese industry case, is applied in order to corroborate the model applicability and adequacy to real world problems.
Mota, Bruna, Maria Isabel Gomes, and Ana P. Barbosa-Povoa. "
Supply Chain Design towards sustainability: accounting for growth and jobs." In
Proceedings of the 8th International Conference on Foundations of Computer-Aided Process Design – FOCAPD 2014, 789-794. Washington, USA, 2014.
AbstractSustainable supply chain design is nowadays an important topic where not only economic and environmental aspects should be accounted for, but also social aspects are to be considered. A mathematical programming model was developed and a case-study was performed considering two different social indicators: one that prefers facility location in regions of lower GDP and the other in regions of higher unemployment rate. Results show that the outcome depends on the indicator used. However, for the case presented, minimum cost solution also corresponds to a good social solution regarding GDP, which could translate into economic incentives for the company.
Santana, Nuno Miguel, Maria Isabel Gomes, and Ana Paula Barbosa-povoa. Supply Chain Optimization: Application to a real case In
Livro de actas do 15º congresso da APDIO, IO2011. Coimbra, Portugal, 2011.
AbstractThe increase focus of companies in clients’ satisfaction, independently of the market they operate in, results from a growing degree of consumers expectations. To fulfill such increase, companies have to arm themselves with the correct internal capabilities, achieving not only efficacy in the satisfaction of each customer, but also efficiency, by operating at the lower possible cost. One of those internal capabilities is the logistics network, which is representing, more and more, a great challenge for companies, given the complexity of the variables that compose it. In this paper, an optimization model is developed that contemplates simultaneously the design and planning of supply chains with reversed flows, through a multi-period and a multi-product network. The proposed model acts as a support tool for the decisions to be made in a real case of a Portuguese telecommunications company, in order to optimize its logistics network.
Pires, Ana, Graca Martinho, Susana Rodrigues, and Maria Isabel Gomes. Sustainable Solid Waste Collection and Management: An Integrated Approach. New York: Springer, 2019.
AbstractThis volume focuses on the collection of waste and waste streams as an integral aspect of sustainable waste management. The authors take economic models and behavioral studies into account to go beyond just descriptions of waste collections technologies and collection route design. Models and tools for sustainable waste collection are described in detail, and the authors provide a comprehensive, integrated methodology to design waste collection systems that reduce environmental impacts, are economically viable, and achieve buy-in and participation from target populations.
Part I of the book provides fundamentals and context on waste hierarchy, including waste prevention, reduction and reuse, waste collection itself, and steps such as preparation for recycling, recycling, treatment, and landfilling. Background in environmental, social, and economic concerns surrounding waste collection is also provided here. Part II addresses tools for design, operation, and maintenance of waste collection systems. Part III focuses on how the tools presented in Part II can be used to support sustainability assessments and decisions that consider the entire life cycle of waste and the role of waste collection programs in waste prevention, reduction, reuse, recycling, treatment, and disposal. Part IV addresses the challenges of developing sustainable waste management systems and addresses the role of waste collection in sustainable waste management in the future.