@proceedings {12866, title = {Design and planning supply chains with beneficial societal goals }, journal = {FOCAPD}, year = {Submitted}, author = {Mota, B. and Carvalho, A. and Gomes, M.I. and Barbosa-Povoa, A P} } @article {12039, title = {Life Cycle Assessment in sustainable supply chain design and planning: the impact of goal and scope definition}, year = {Submitted}, author = {Mota, Bruna and Carvalho, Ana and Gomes, Maria Isabel and Barbosa-povoa, Ana Paula} } @article {12041, title = {Metaheuristic method to evaluate the fire risk sub-module in Solvency II}, year = {Submitted}, author = {Afonso, Lourdes B and Fradinho, Joana and Chibeles-Martins, Nelson and Gomes, Maria Isabel} } @article {11401, title = {A new matheuristic approach for the Multi-Depot Vehicle Routing Problem with Inter-Depot Routes}, year = {Submitted}, author = {Ramos, T.R.P. and Gomes, M.I. and Barbosa-P{\'o}voa, A.P.} } @article {13166, title = {Business strategy for sustainable development: impact of Life Cycle Inventory and Life Cycle Impact Assessment steps in supply chain design and planning}, journal = {Journal of Business Strategy and Environment }, year = {In Press}, author = {Mota, B. and Carvalho, A. and Gomes, M.I. and Barbosa-Povoa, A P} } @article {13255, title = {Multi-depot vehicle routing problem: a comparative study of alternative formulations}, journal = {International Journal of Logistics Research and Applications}, year = {In Press}, author = {Ramos, T.R.P. and Gomes, M.I. and Barbosa-Povoa, A P} } @article {11398, title = {Patterns of Sexual Risk Behavior, HIV Infection, and Use of Health Services Among Sub-Saharan African Migrants in Portugal.}, journal = {The Journal of Sex Research 19}, year = {In Press}, url = {https://www.tandfonline.com/doi/abs/10.1080/00224499.2019.1601154?journalCode=hjsr20}, author = {Dias, S. and Gama, A. and Abrantes, P. and Gomes, M.I. and Fonseca, M and Reigado, V and Sim{\~o}es, D and Carreiras, E and Mora, C and Pinto Ferreira, A and Akpogheneta, O and Martins, MO} } @article {11134, title = {Modelling and (Re-)Planning Periodic Home Social Care Services with Loyalty and Non-Loyalty Features}, journal = {European Journal of Operational Research}, volume = {277}, year = {2019}, pages = {284-299}, url = {https://www.sciencedirect.com/science/article/abs/pii/S0377221719300967}, author = {Gomes, Maria Isabel and Ramos, Tania} } @article {11400, title = {On risk management of a two-stage stochastic mixed 0-1 model for the closed-loop supply chain design problem}, journal = {European Journal of Operational Research}, volume = {274}, year = {2019}, pages = {91-107}, abstract = {

In this work, the design and operation planning of a multi-period, multi-product closed-loop supply chain is addressed. Recovered end-of-life products from customers are evaluated in disassembly centers and accordingly are sent back to factories for remanufacturing, or leave the network either by being sold to third parties or by being sent to disposal. Typical uncertain parameters are product demand, production cost, and returned product volume and evaluation, among others. So, stochastic optimization approaches should be used for problem solving, where different topology decisions on the timing, location and capacity of some entities (factories, and distribution and sorting centers) are to be considered along a time horizon. A two-stage multi-period stochastic mixed 0{\textendash}1 bilinear optimization model is introduced, where the combined definition of the available entities at the periods and the products{\textquoteright} flow among the entities, maximizes the net present value of the expected total profit along the time horizon. A version of the mixture of chance-constrained and second order stochastic dominance risk averse measures is considered for risk management at intermediate periods of the time horizon. Given the high dimensions of the model it is unrealistic to look for the optimality of the solution in an affordable computing effort for current hardware and optimization software resources. So, a decomposition approach is considered, namely a Fix-and-Relax decomposition algorithm. For assessing the computational validation of the modeling and algorithmic proposals, pilot cases are taken from a real-life glass supply chain network whose main features are retained.

}, url = {https://www.sciencedirect.com/science/article/abs/pii/S0377221718308233}, author = {Baptista, S. and Barbosa-P{\'o}voa, A.P. and Escudero, L. and Gomes, M.I. and Pizarro, C,} } @book {12042, title = {Sustainable Solid Waste Collection and Management: An Integrated Approach}, year = {2019}, publisher = {Springer}, organization = {Springer}, address = {New York}, abstract = {

This 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.

}, url = {https://www.springer.com/us/book/9783319931999}, author = {Pires, Ana and Martinho, Graca and Rodrigues, Susana and Gomes, Maria Isabel} } @conference {11133, title = {A Biased-Randomized Heuristic for the Home Healthcare Routing Problem}, booktitle = {IO 2017, in {\textquotedblright}, Springer Proceedings in Mathematics and Statistics series}, year = {2018}, address = {Valen{\c c}a, Portugal}, author = {Eliseu, Manuel and Gomes, Maria Isabel and Juan, Angel A} } @proceedings {12864, title = {Continuous Reinforcement Operator applied to Resilience in Disaster Rescue Networks}, journal = {2018 IEEE International Conference on Fuzzy Systems (FUZZ-IEEE)}, year = {2018}, pages = {1-7}, author = {Jassbi, Javad J and Rita A. Ribeiro and Camarinha-Matos, Luis M and Barata, Jos{\'e} and Gomes, Maria Isabel} } @proceedings {11396, title = {Green supply chain design and planning: the importance of decision integration in optimization models}, journal = {IO 2017, Springer Proceedings in Mathematics and Statistics serie}, year = {2018}, pages = {249-257}, publisher = {Springer Proceedings in Mathematics and Statistics, 223}, address = {Valen{\c c}a, Portugal}, attachments = {https://docentes.fct.unl.pt/sites/default/files/mirg/files/2018_motaetal_greensupplychain_io2017.pdf}, author = {Mota, B. and Carvalho, A. and Gomes, M.I. and Barbosa-P{\'o}voa, A.P.} } @proceedings {12040, title = {Multi-start local search procedure for the maximum fire risk insured capital problem}, journal = {International Symposium on Combinatorial Optimization}, year = {2018}, pages = {219-227}, address = {Marrakech, Marroco}, author = {Gomes, Maria Isabel and Afonso, Lourde B and Chibeles-Martins, Nelson and Fradinho, Joana} } @article {Mota2017, title = {Sustainable supply chains: an integrated modelling approach under uncertainty}, journal = {Omega}, volume = {77}, year = {2018}, note = {

n/a

}, pages = {32-57}, abstract = {

Abstract This work presents ToBLoOM {\textendash} Triple Bottom Line Optimization Modelling, a decision support tool for the design and planning of sustainable supply chains. It consists of a multi-objective mixed integer linear programming model which integrates several interconnected decisions: facility location and capacity determination; supplier selection and purchase levels definition; technology selection and allocation; transportation network definition including both unimodal and intermodal options; supply planning; product recovery and remanufacturing. The three pillars of sustainability are addressed as objective functions: economic, through Net Present Value; environmental through the Life Cycle Analysis methodology ReCiPe; and social through a developed GDP-based metric. Uncertainty is considered using a stochastic ToBloOM. This applied to a case of a European based company with markets in Europe and South America. This work contributes to the literature by building on several identified research gaps such as the need for an integrated approach that allows simultaneous assessment of different interacting supply chain decisions, the need to explicitly assess the environmental impact in closed-loop supply chains, the need to assess the impact of supply chains on society, and the need for a multi-objective tool that includes all the three pillars of sustainability. Strategies towards a more sustainable supply chain are also derived from this work.

}, keywords = {stochastic optimization}, issn = {0305-0483}, doi = {https://doi.org/10.1016/j.omega.2017.05.006}, url = {http://www.sciencedirect.com/science/article/pii/S0305048317304401}, attachments = {https://docentes.fct.unl.pt/sites/default/files/mirg/files/2017_motagomescarvalhobpovoa_omega.pdf}, author = {Mota, Bruna and Gomes, Maria Isabel and Carvalho, Ana and Barbosa-povoa, Ana Paula} } @proceedings {11397, title = {Sustainable supply chain design and planning: the importance of life cycle scope definition}, journal = {Computer Aided Chemical Engineering, 40}, year = {2017}, month = {1-5 Oct}, pages = {541-546}, publisher = {Elsevier}, address = {Barcelona, Spain}, author = {Mota, B. and Carvalho, A. and Gomes, M.I. and Barbosa-P{\'o}voa, A.P.} } @article {11399, title = {Selfie ageing index: an index for the self-assessment of healthy and active ageing}, journal = {Frontiers in Medicine}, volume = {4}, year = {2017}, attachments = {https://docentes.fct.unl.pt/sites/default/files/mirg/files/2017_goncalvesgomes_et_al_frontiersinmedicine.pdf}, author = {Gon{\c c}alves, J. and Gomes, M.I. and Fonseca, M and Teodoro, T. and Pita Barros, P. and Botelho, M.A.} } @article {Calvet2016, title = {Combining statistical learning with metaheuristics for the multi-depot vehicle routing problem with market}, journal = {Computers \& Industrial Engineering}, volume = {94}, year = {2016}, note = {

n/a

}, pages = {93{\textendash}104}, publisher = {Elsevier Ltd}, abstract = {

n/a

}, keywords = {market segmentation applications, multi-depot vehicle routing problem}, issn = {0360-8352}, doi = {10.1016/j.cie.2016.01.016}, url = {http://dx.doi.org/10.1016/j.cie.2016.01.016}, attachments = {https://docentes.fct.unl.pt/sites/default/files/mirg/files/2016_calvetferrergomesjuanmasip.pdf}, author = {Calvet, Laura and Ferrer, Albert and Gomes, M. Isabel and Juan, Angel A and Masip, David} } @inbook {6493, title = {The influence of Corporate Social Responsibility on economic performance within supply chain planning}, booktitle = {Computational Management Science: State of the Art 2014}, year = {2016}, pages = {151-156}, publisher = {Springer}, organization = {Springer}, attachments = {https://docentes.fct.unl.pt/sites/default/files/mirg/files/2014_motagomescarvalhobpovoa_cms_0.pdf}, author = {Mota, Bruna and Gomes, Maria Isabel and Carvalho, Ana and Barbosa-povoa, Ana Paula}, editor = {Raquel J. Fonseca and Gerhard-Wilhelm Weber and Joan Telhada} } @inbook {6490, title = {Design and planning of sustainable supply chains}, booktitle = {Sustainability of Products, Processes and Supply Chains: Theory and Applications}, year = {2015}, pages = {333-353}, publisher = {Elsevier}, organization = {Elsevier}, address = {Amsterdam}, author = {Mota, Bruna and Carvalho, Ana and Gomes, Maria Isabel and Barbosa-povoa, Ana Paula}, editor = {Fengqi You} } @article {3415, title = {Designing Closed-Loop Supply Chains with Nonlinear Dimensioning Factors Using Ant Colony Optimization}, journal = {Soft Computing}, volume = {19}, year = {2015}, pages = {2245-2264}, url = {http://link.springer.com/article/10.1007\%2Fs00500-014-1405-7}, attachments = {https://docentes.fct.unl.pt/sites/default/files/mirg/files/2015_vieiravieiragomessousabpovoa_softcomp.pdf}, author = {Vieira, P. F. and Susana M. Vieira and Sousa, J.M.C and Gomes, Maria Isabel and Barbosa-p{\'o}voa, Ana Paula} } @inbook {Baptista2015, title = {A Fix-and-Relax Algorithm for Solving Parallel and Sequential Versions of a Multi-period Multi-product Closed Loop Supply Chain Design and Operation Planning Model}, booktitle = {Operations Research and Big Data: IO2015-XVII Congress of Portuguese Association of Operational Research (APDIO)}, year = {2015}, note = {

n/a

}, pages = {9{\textendash}14}, publisher = {Springer International Publishing}, organization = {Springer International Publishing}, chapter = {A Fix-and-Relax Algorithm for Solving Parallel and Sequential Versions of a Multi-period Multi-product Closed Loop Supply Chain }, abstract = {

n/a

}, isbn = {978-3-319-24154-8}, doi = {10.1007/978-3-319-24154-8_2}, url = {http://dx.doi.org/10.1007/978-3-319-24154-8_2}, attachments = {https://docentes.fct.unl.pt/sites/default/files/mirg/files/2015_baptistagomesescuderomedeiroscabrita_io2015.pdf}, author = {Baptista, Susana and Gomes, Maria Isabel and Escudero, Laureano and Medeiros, Pedro and Cabrita, Filipe}, editor = {P{\'o}voa, Barbosa Ana Paula Ferreira Dias and de Miranda, Luis Joao} } @proceedings {Mota2015, title = {Green Supply Chain Design and Planning}, journal = {Proceedings of 2015 International Conference on Industrial Engineering and Systems Management (IESM),}, number = {November}, year = {2015}, note = {

n/a

}, pages = {537{\textendash}545}, publisher = {I4 e2 - M. Goudalier}, abstract = {

A Mixed Integer Linear Programming model for the design and planning of green supply chains is developed. Strategic and tactical decisions are taken, namely on facility location and capacity installation, supplier selection, technology selection, transportation network definition, supply planning, and product recovery. The aim of this work is to study the use of environmental indicators in these decisions while accounting for profit objectives. Different objective functions concerning environmental aspects are implemented. ReCiPe quantifies the environmental performance of the supply chain and combinations of ReCiPe{\textquoteright}s midpoint categories allow a deeper analysis of the impact of these categories in strategic and tactical decisions. The goal is to understand if focusing on selected categories affects supply chain decisions and overall supply chain environmental impact. Net Present Value quantifies the economic performance and is used for lexicographic optimization. The model is applied to a case-study and important managerial insights are obtained. From a holistic point of view, it answers the question: how should supply chain environmental impact be assessed? From a case-study perspective, insights are obtained regarding what type of improvements should be implemented to reduce the environmental impact and how this would affect supply chain strategic and tactical decisions, along with economic performance.

}, keywords = {closed-loop}, url = {http://www.i4e2.org/iesm15/free{\_}access{\_}documents/proceedings{\_}outlines.pdf}, attachments = {https://docentes.fct.unl.pt/sites/default/files/mirg/files/2015_motacarvalhogomesbpovoa_iesm2015.pdf}, author = {Mota, Bruna and Carvalho, Ana and Gomes, Maria Isabel and Barbosa-povoa, Ana Paula}, editor = {Framinan, J.M. and Perez Gonzalez, P. and Artiba, A.} } @conference {6824, title = {A Metaheuristic for Solving Large-Scale Two-Stage Stochastic Mixed 0-1 Programs with the Time Stochas- tic Dominance Risk Averse Strategy}, booktitle = {12th International Symposium on Process Systems Engineering and 25th European Symposium on Computer Aided Process Engineering. }, year = {2015}, pages = {857-862}, publisher = {Elsevier}, organization = {Elsevier}, address = {Copenhagen, Denmark }, abstract = {

Supply Chain Design problems often result into multiperiod stochastic mixed integer problems that are hard to solve. In this paper we propose a metaheuristic algorithm as a specialization for two- stage problems of the so-named Fix-and-Relax Algorithm presented previously for solving large- scale multiperiod stochastic mixed 0-1 optimization problems under a time stochastic dominance risk averse strategy, so-named TSD. Some computational experience is presented.

}, attachments = {https://docentes.fct.unl.pt/sites/default/files/mirg/files/escape25.pdf}, author = {Baptista, Susana and Barbosa-povoa, Ana Paula and Escudero, Laureano and Gomes, Maria Isabel and Pizarro, Celeste} } @conference {6823, title = {Supply chain design and planning accounting for the Triple Bottom Line}, booktitle = {12th International Symposium on Process Systems Engineering and 25th European Symposium on Computer Aided Process Engineering. }, year = {2015}, pages = {1842-1846}, publisher = {Elsevier}, organization = {Elsevier}, address = {Copenhagen, Denmark }, abstract = {

In 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.

}, attachments = {https://docentes.fct.unl.pt/sites/default/files/mirg/files/escape25_0.pdf}, author = {Mota, Bruna and Gomes, Maria Isabel and Carvalho, Ana and Barbosa-povoa, Ana Paula} } @article {5738, title = {Towards supply chain sustainability: economic, environmental and social design and planning}, journal = {Journal of Cleaner Production}, volume = {105}, year = {2015}, pages = {14-27}, url = {http://www.sciencedirect.com/science/article/pii/S0959652614007719}, attachments = {https://docentes.fct.unl.pt/sites/default/files/mirg/files/2015_motagomescarvalhobpovoa_jcp.pdf}, author = {Mota, Bruna and Gomes, Maria Isabel and Carvalho, Ana and Barbosa-Povoa, Ana P.} } @conference {6491, title = {Supply chain environmental assessment}, booktitle = {avniR Conference}, year = {2014}, month = {5-6 Nov}, address = {Nouveau Si{\`e}cle, Lille, France}, attachments = {https://docentes.fct.unl.pt/sites/default/files/mirg/files/2014_motacarvalhogomesbpovoa_avnir.pdf}, author = {Mota, Bruna and Carvalho, Ana and Gomes, Maria Isabel and Barbosa-povoa, Ana Paula} } @conference {5303, title = {Supply Chain Design towards sustainability: accounting for growth and jobs}, booktitle = {Proceedings of the 8th International Conference on Foundations of Computer-Aided Process Design {\textendash} FOCAPD 2014}, year = {2014}, month = {13-17 July}, pages = {789-794}, address = {Washington, USA}, abstract = {

Sustainable 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.

}, url = {http://www.sciencedirect.com/science/article/pii/B9780444634337501164}, attachments = {https://docentes.fct.unl.pt/sites/default/files/mirg/files/2014__motagomesbpovoa_focapd_va.pdf}, author = {Mota, Bruna and Gomes, Maria Isabel and Barbosa-Povoa, Ana P.} } @article {Ramos2014, title = {Assessing and improving management practices when planning packaging waste collection systems}, journal = {Resources, Conservation and Recycling}, volume = {85}, year = {2014}, pages = {116-129}, abstract = {

Packaging waste collection systems are responsible to collect, within a geographic area, three types of packaging materials (paper, glass and plastic/metal) that are disposed by the final consumer into special bins. Those systems are often characterized by having a network with multiple depots that act as transfer and sorting stations, and where the vehicle fleet is based. However, each depot is often managed independently and not as a part of a unique system. In this work, four current tactical/operational practices that contribute to the independent management of each depot are analysed. The change of such practices is investigated and their impact assessed on the total collection cost. A solution methodology based on mathematical formulations is developed to plan service areas, vehicle routes and vehicle schedules taking into account new alternative solutions in managing the system as a whole. Such methodology is applied to a real case study of a company responsible for the collection of the packaging waste in 7 municipalities in mainland Portugal. New service areas, collection routes and vehicle schedules are defined and significant savings are obtained in terms of the total distance travelled as well as in terms of the number of required vehicles, resulting in a decreasing of the total system cost.

}, keywords = {This paper proposes a systematic methodology for supply chain planning optimization and assessment of different scenarios. This methodology will help companies throughout the difficult process of strategic decision-making in what concerns the design of an efficient supply chain structure. The proposed methodology allows the analysis of complex systems as it integrates a decision support tool developed to agile the process of scenario comparison, when designing network structures. This tool allows practitioners to take advantage of the optimization models without the need of learning modelling languages. An example based on a real case study is presented, showing the methodology/tool applicability.

}, url = {http://www.sciencedirect.com/science/article/pii/B9780444634566501502}, attachments = {https://docentes.fct.unl.pt/sites/default/files/mirg/files/2014_costagomescarvalhobpovoa_escape24.pdf}, author = {Costa, Pedro and Gomes, Maria Isabel and Carvalho, Ana and Barbosa-Povoa, Ana P.} } @article {3217, title = {Economic and environmental concerns in planning recyclable waste collection systems}, journal = {Transportation Research Part E: Logistics and Transportation Review}, volume = {62}, year = {2014}, pages = {34-54}, abstract = {

This paper addresses the planning of recyclable waste collection systems while accounting for economic and environmental concerns. Service areas and vehicle routes are defined for multiple-depot logistics networks where different products have to be collected. The problem is modeled as a multi-product, multi-depot vehicle routing problem with two objective functions: distance and CO2 emissions minimization. A decomposition solution method is developed and applied to a real case-study. Six scenarios are studied regarding different service areas configuration and different objective functions. Savings up to 22\% in distance and 27\% in CO2 emissions are achieved, excelling economical and environmental goals.

}, url = {http://www.sciencedirect.com/science/article/pii/S1366554513001968}, author = {Ramos, Tania Rodrigues Pereira and Gomes, Maria Isabel and Barbosa-p{\'o}voa, Ana Paula} } @article {3215, title = {Planning a sustainable reverse logistics system: balancing costs with environmental and social concerns}, journal = {Omega}, volume = {48}, year = {2014}, pages = {60-74}, abstract = {

The present work aims to support tactical and operational planning decisions of reverse logistics systems while considering economical, environmental and social objectives. In the literature, when addressing such systems economical aspects have been often used, while environmental concerns have been only recently emerging. The social component is the one less studied, and rarely the combination of the three concerns has been analyzed. This work address the three objectives and was motivated by the challenge of supporting decisions makers when managing a real case study of a recyclable waste collection system, where strategic decisions on the number and location of depots, vehicles and containers were taken beforehand. Tactical and operational decisions are studied involving the establishment of service areas for each depot and the definition and scheduling of collection routes for each vehicle. Such decisions should represent a compromise solution between the three objectives considered and support a sustainable reverse logistics plan. A multi-objective solution approach based on mixed-integer linear programming models is developed. Trade-offs between the objectives are discussed. Moreover the solutions obtained when each objective is tackled individually are compared between themselves and with the balanced solution.

}, author = {Ramos, Tania Rodrigues Pereira and Gomes, Maria Isabel and Barbosa-p{\'o}voa, Ana Paula} } @inbook {6780, title = {Projeto de uma rede log{\'\i}stica para a recolha de equipamentos el{\'e}tricos e eletr{\'o}nicos}, booktitle = {Investiga{\c c}{\~a}o Operacional em A{\c c}{\~a}o. Casos de Aplica{\c c}{\~a}o}, year = {2014}, note = {

(em portugu{\^e}s)

}, pages = {399 - 434}, publisher = {Imprensa da Universidade de Coimbra }, organization = {Imprensa da Universidade de Coimbra }, address = {Coimbra}, author = {Gomes, Maria Isabel and P{\'o}voa, Ana Paula Barbosa}, editor = {Rui Carvalho Oliveira and Jos{\'e} Soeiro Ferreira} } @inbook {6781, title = {Reestrutura{\c c}{\~a}o de {\'a}reas de influ{\^e}ncia e de rotas de ve{\'\i}culos num sistema de recolha de res{\'\i}duos recicl{\'a}veis}, booktitle = {Investiga{\c c}{\~a}o Operacional em A{\c c}{\~a}o. Casos de Aplica{\c c}{\~a}o}, year = {2014}, note = {

(em portugu{\^e}s)

}, pages = {435 - 471}, publisher = {Imprensa da Universidade de Coimbra }, organization = {Imprensa da Universidade de Coimbra }, address = {Coimbra}, author = {Ramos, Tania Rodrigues Pereira and Gomes, Maria Isabel and P{\'o}voa, Ana Paula Barbosa}, editor = {Rui Carvalho Oliveira and Jos{\'e} Soeiro Ferreira} } @conference {4868, title = {Recyclable packaging waste collection systems: redesigning service areas and collection routes in a real case-study}, booktitle = {2nd International Conference WASTES: Solutions, Treatments and Opportunities}, year = {2013}, month = {September}, address = {Braga, Portugal}, abstract = {

This paper addresses the planning of a real recyclable packaging waste collection system operating in Portugal. The company{\textquoteright}s logistics network is characterized by the existence of multiple depots and multiple products to be collected in each site. Service areas and vehicle routes are currently defined respecting the municipal boundaries and present a need for improvement. To study this problem mixed integer linear programming formulations have been developed allowing the redesign of service areas and of collection routes under two scenarios, respectively, considering the definition of service areas by depot and by material. The scenario where the current service areas are maintained and the collection routes are optimized is also studied. Savings up to 20\% in total distance are achieved by redesigning service areas and collection routes.

}, attachments = {https://docentes.fct.unl.pt/sites/default/files/mirg/files/2013_ramosgomesbpovoa_wastes2013.pdf}, author = {Ramos, Tania and Gomes, Maria Isabel and Barbosa-povoa, Ana Paula} } @article {3218, title = {Planning Waste Cooking Oil Collection Systems}, journal = {Waste Management}, volume = {33}, year = {2013}, pages = {1691-1703}, abstract = {

This research has been motivated by a real-life problem of a waste cooking oil collection system characterized by the existence of multiple depots with an outsourced vehicle fleet, where the collection routes have to be plan. The routing problem addressed allows open routes between depots, i.e., all routes start at one depot but can end at the same or at a different one, depending on what minimizes the objective function considered. Such problem is referred as a Multi-Depot Vehicle Routing Problem with Mixed Closed and Open Inter-Depot Routes and is, in this paper, modeled through a Mixed Integer Linear Programming (MILP) formulation where capacity and duration constraints are taken into account. The model developed is applied to the real case study providing, as final results, the vehicle routes planning where a decrease of 13\% on mileage and 11\% on fleet hiring cost are achieved, when comparing with the current company solution.

}, url = {http://linkinghub.elsevier.com/retrieve/pii/S0956053X13001748}, author = {Ramos, Tania Rodrigues Pereira and Gomes, Maria Isabel and Barbosa-p{\'o}voa, Ana Paula} } @conference {Baptista2013, title = {A stochastic model for a multi-period multi-product closed loop supply chain}, booktitle = {XVI Congresso da Associa{\c c}{\~a}o Portuguesa de Investiga{\c c}{\~a}o Operacional IO 2013}, year = {2013}, pages = {27{\textendash}37}, address = {Bragan{\c c}a, Portugal}, abstract = {

In 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.

}, url = {https://bibliotecadigital.ipb.pt/handle/10198/8451}, attachments = {https://docentes.fct.unl.pt/sites/default/files/mirg/files/2013_baptistagomesbpovoa_io2013.pdf}, author = {Baptista, Susana and Gomes, Maria Isabel and Barbosa-p{\'o}voa, Ana Paula} } @conference {Ramos2013, title = {Tactical and Operational Planning in Reverse Logistics Systems with Multiple Depots}, booktitle = {XVI Congresso da Associa{\c c}{\~a}o Portuguesa de Investiga{\c c}{\~a}o Operacional IO 2013}, year = {2013}, pages = {286{\textendash}295}, address = {Bragan{\c c}a, Portugal}, keywords = {multiple depots, reverse logistics, rout-, service areas, sustainability, waste collection}, url = {https://bibliotecadigital.ipb.pt/handle/10198/8451}, attachments = {https://docentes.fct.unl.pt/sites/default/files/mirg/files/2013_ramosgomesbpovoa_io2013.pdf}, author = {Ramos, T{\^a}nia and Gomes, Maria Isabel and Barbosa-p{\'o}voa, Ana Paula} } @inbook {3416, title = {Towards supply chain sustainability: balancing costs with environmental and social impacts}, booktitle = {Computer Aided Process Engineering}, year = {2013}, pages = {895-900}, publisher = {Elsevier}, organization = {Elsevier}, abstract = {

This work presents a multi-objective optimization methodology that accounts for economic, environmental and social concerns in a supply chain with reverse flows. Environmental impact assessment is considered through the use of Recipe 2008. A social benefit indicator is developed where the creation of employment in less developed regions is preferred. The multi-objective approach is used to reach a solution of compromise between the three sustainability pillars. The model is applied to a case study developed in collaboration with a Portuguese company, leader in battery production.

}, url = {http://www.sciencedirect.com/science/article/pii/B9780444632340501500}, attachments = {https://docentes.fct.unl.pt/sites/default/files/mirg/files/2013_motagomesbpovoa_escape23.pdf}, author = {Mota, Bruna and Gomes, Maria Isabel and Barbosa-p{\'o}voa, Ana Paula}, editor = {Andrzej Kraslawski and Ilkka Turunen} } @conference {2824, title = {SCant-design: Closed loop supply chain design using ant colony optimization}, booktitle = {2012 IEEE Congress on Evolutionary Computation (CEC)}, year = {2012}, month = {10-15 Jun.}, address = {Brisbane, Australia}, abstract = {

This 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.

}, url = {http://ieeexplore.ieee.org/xpl/articleDetails.jsp?tp=\&arnumber=6252944\&contentType=Conference+Publications\&refinements\%3D4293214331\%26sortType\%3Dasc_p_Sequence\%26filter\%3DAND\%28p_IS_Number\%3A6252855\%29}, attachments = {https://docentes.fct.unl.pt/sites/default/files/mirg/files/preprint_esteves_et_al._-_2012_-_scant-design_closed_loop_supply_chain_design_using_ant_colony_optimization.pdf}, author = {Esteves, V.M.C. and Sousa, J.M.C and Silva, C.A and Povoa, A.P.B and Gomes, M.I.} } @article {Zeballos2012, title = {Addressing the uncertain quality and quantity of returns in closed-loop supply chains}, journal = {Computers \& Chemical Engineering}, volume = {47}, year = {2012}, pages = {237-247}, publisher = {Elsevier Ltd}, abstract = {

In this work a two-stage scenario-based modeling approach is proposed in order to simultaneously deal with the design and planning decisions in supply chain networks, where both forward and reverse flows are considered (closed-loop supply chains) subject to uncertain conditions. A mixed integer linear programming (MILP) approach is developed with the underlying objective of profit maximization. Planning takes into account raw material acquisition and processing, storage and distribution of several products flowing through the network. Uncertainty is associated to the quantity and quality of the flow of products of the reverse network, which are directly affected by customers and sorting centers, respectively. The approach considers, by means of scenarios, the simultaneous integration of two important uncertainty sources, thus presenting an important modeling advantage, i.e. that of providing a better understanding of the CLSCs. The applicability of the formulation is tested with a real sized example of a Portuguese glass company.

}, keywords = {closed-loop supply chain}, issn = {00981354}, doi = {10.1016/j.compchemeng.2012.06.034}, url = {http://linkinghub.elsevier.com/retrieve/pii/S0098135412002189}, author = {Zeballos, Luis J. and Gomes, Maria Isabel and Barbosa-Povoa, Ana P. and Novais, Augusto Q.} } @conference {Ramos2012, title = {Minimizing CO2 Emissions in a Recyclable Waste Collection System with Multiple Depots}, booktitle = {EUROMA/POMS Joint Conference}, year = {2012}, note = {

n/a

}, pages = {1{\textendash}11}, abstract = {

n/a

}, keywords = {greenhouse gas emissions, multi-depot vehicle routing, service areas}, attachments = {https://docentes.fct.unl.pt/sites/default/files/mirg/files/euroma_2012_fullpaper_final.pdf}, author = {Ramos, Tania Rodrigues Pereira and Gomes, Maria Isabel and Barbosa-p{\'o}voa, Ana Paula} } @inbook {Zeballos2012407, title = {Optimum Design and Planning of Resilient and Uncertain Closed-Loop Supply Chains}, booktitle = {22nd European Symposium on Computer Aided Process Engineering}, series = {Computer Aided Chemical Engineering}, volume = {30}, number = {June}, year = {2012}, pages = {407{\textendash}411}, publisher = {Elsevier}, organization = {Elsevier}, address = {London}, abstract = {

The design and planning of efficient supply chains (SC) is a major challenge that increases when the return of products has to be accounted for, the so-called closed-loop supply chains (CLSC). In the present work the effect of disruptions and modifications in the operating conditions of CLSCs are investigated on the basis of a 2-stage scenario based model previously developed by the authors. Metrics derived from graph theory are used, along with more conventional economic and operational indices. A discussion on the results obtained is presented to assess how the design and planning of the CLSC respond to these challenges and how these metrics may contribute to this objective.

}, keywords = {closed-loop supply chain, Design and Planning, Resilience, Uncertainty}, issn = {1570-7946}, doi = {10.1016/B978-0-444-59519-5.50082-4}, url = {http://www.sciencedirect.com/science/article/pii/B9780444595195500824}, author = {Zeballos, L J and Gomes, M.I. and Barbosa-Povoa, A P and Novais, A Q}, editor = {Bogle, Ian David Lockhart and Fairweather, Michael} } @inbook {Baptista2012412, title = {A Two-Stage Stochastic Model for the Design and Planning of a Multi-Product Closed Loop Supply Chains}, booktitle = {22nd European Symposium on Computer Aided Process Engineering}, series = {Computer Aided Chemical Engineering}, volume = {30}, number = {June}, year = {2012}, pages = {412{\textendash}416}, publisher = {Elsevier}, organization = {Elsevier}, address = {London}, abstract = {

In this paper we address the problem of uncertainty in the design and planning of a multi-period, multi-product closed loop supply chain, where the recovered products are end-of-life products that are disassembled and recycled. Uncertainty is explicitly modelled by considering customers{\textquoteright} demands and returns to be stochastic. A two{\textendash}stage model is developed where first stage decisions concern the facility location while second stage decisions are the production planning of the supply chain. The integer L- shaped method was adopted as the solution tool and computational tests were performed on multi-period and multi-commodity networks randomly generated based on a reference case. A comparison between the proposed solution method and the straight use of the CPLEX is performed.

}, keywords = {closed-loop supply chain, Design and Planning, two-stage stochastic, Two-stage Stochastic Optimization}, issn = {1570-7946}, doi = {10.1016/B978-0-444-59519-5.50083-6}, url = {http://www.sciencedirect.com/science/article/pii/B9780444595195500836}, attachments = {https://docentes.fct.unl.pt/sites/default/files/mirg/files/preprint_baptistagomesbarbosa-povoa2012_escape22.pdf}, author = {Baptista, Susana and Gomes, Maria Isabel and Barbosa-povoa, Ana Paula}, editor = {Bogle, Ian David Lockhart and Fairweather, Michael} } @conference {3417, title = {Uncertain quality and quantity of returns in a closed-loop supply chain}, booktitle = { Foundations of Computer-aided Process Operations}, year = {2012}, address = {Savannah, USA}, abstract = {

In this work the design and planning of a Closed-Loop Supply Chain (CLSC) under uncertain conditions is considered and a two-stage scenario-based modeling approach is proposed in order to deal with this multi-product, multi-period problem. The network design and tactical plan are simultaneously optimized in a given time horizon, comprehending the raw material acquisition and the processing, storage and distribution of intermediates, returns and final products. Uncertainty is associated to the returns, both in terms of their quantity, which is customer dependent, and quality, which is determined at the sorting centers. Therefore, the ensuing mathematical MILP formulation considers the simultaneous integration of two important uncertainty sources, which represents an important modeling advantage, allowing a better understanding of the reverse network structure. For each probabilistic scenario, the model estimates the amount of products to be returned by customers and of returns to be remanufactured for each quality level, as well as the storage levels. Several tests based on a real sized example of a Portuguese glass company are undertaken in order to show the applicability of the developed approach. Based on these tests, the influence of the uncertain quality and quantity of returns on the design and planning of the CLSC is assessed.

}, url = {http://focapo.cheme.cmu.edu/2012/proceedings/data/papers/046.pdf}, author = {Zeballos, Luis J. and Gomes, Maria Isabel and Barbosa-p{\'o}voa, Ana Paula and Novais, Augusto Q.} } @inbook {Furtado2011, title = {Design of an electric and electronic equipment recovery network in Portugal {\textendash} Costs vs. Sustainability}, booktitle = {Computer Aided Chemical Engineering}, volume = {29}, year = {2011}, note = {

n/a

}, pages = {1200{\textendash}1204}, abstract = {

In the last few decades there has been a massive growth in the Waste of Electric and ElectronicEquipment (WEEE). Part of these residues was already properly treated in some countries, but the lack of environmentally friendly options forced the European Union (EU) to take action. Two EU directives were created based on reduction, reutilization and recycling of WEEE. The need to properly designrecoverynetworks for such products appears as mandatory, where not only the economic aspects should be accounted for but also the environmental ones. The present paper addresses this problem and presents a generic optimization model for the design and planning of a recovery and treatment network of WEEE, minimizing both the costs and the environmental impacts that arise from the activity performed.

The model is applied to the real case of Amb3E, the Portuguese Association for the Management of Waste of Electric and ElectronicEquipment. Since its formation, in 2006, this organization has been registering an immense growth in the volume of residue collected, and faces now the necessity of reformulating its recoverynetwork. Both the actual cost structure and the best possible cost structure for Amb3E, given by the optimization of the model, are analyzed. These two scenarios are compared in order to turn clear the differences between them and to assess how the recoverynetwork of Amb3E can be improved through optimization. A similar analysis is performed from an environmental impacts perspective.

}, keywords = {cost, environmental impact, optimization, recovery network, weee}, doi = {10.1016/B978-0-444-54298-4.50019-2}, url = {http://www.sciencedirect.com/science/article/pii/B9780444542984500192}, author = {Furtado, Pedro and Gomes, Maria Isabel and Barbosa-povoa, Ana Paula}, editor = {Pistikopoulos, E.N. and Georgiadis, M.C. and Kokossis, A.C.} } @proceedings {Fradinho2011, title = {Optimization of Batteries Sustainable Distribution Network with Reverse Flows}, journal = {Livro de actas do 15{\textordmasculine} congresso da APDIO, IO2011}, year = {2011}, pages = {13-24}, address = {Coimbra, Portugal}, abstract = {

Optimized supply chains, both economically as well as environmentally, are significant instruments to be adopted by companies if they want to succeed in the current competitive world. However, without the support of decision tools to help, at least approximately, the integration of these two aspects in the company{\textquoteright}s decision making such aim is difficult to reach. The purpose of this study is to develop a mixed integer linear programming model (MILP), which allows the optimization of closed loop supply chains, considering not only economical aspects, but also environmental ones. The model developed was applied to a Portuguese company where their logistic network structure was redesigned.

}, keywords = {close-loop supply chain, economical optimization, environmental, optimization, warehouses location}, attachments = {https://docentes.fct.unl.pt/sites/default/files/mirg/files/2011_fradinhogomesbpovoa_optimizationofbatteriesnewtork_io2011.pdf}, author = {Fradinho, Andre and Gomes, Maria Isabel and Barbosa-p{\'o}voa, Ana Paula} } @inbook {Gomes2011, title = {Optimization of Closed-Loop Supply Chains under Uncertain Quality of Returns}, booktitle = {21st European Symposium on Computer Aided Process Engineering}, volume = {29}, year = {2011}, pages = {945{\textendash}949}, abstract = {

The efficient design and operation of supply chains with return flows represent a major optimization challenge, given the high number of factors involved and their intricate interactions. In particular, the quality level of the return products has strong economic and societal implications and depends greatly on the type of product (glass, paper, electronic, oil, etc) and on the degree of consumers{\textquoteright} readiness, frequently promoted by various kinds of awareness raising campaigns. A multi-product multi-period model was previously developed by the authors [1] for the closed-loop supply chain (CLSC) design and planning, where strategic and tactical decisions were comprehensively considered. This model is now being extended to handle the uncertainty related to the quality of the returned products, which at this stage is modeled by a two-stage scenario-based stochastic approach. General strategies to solve optimization problems involving uncertainty tend to exhibit poor computational performance, due to the problem NP-hard complexity, which tends to worsen with the problem size. Therefore and, in addition, a model performance solution enhancement is also being explored. To increase the efficiency of the solution approach, an alternative representation to some of the integer variables employed in the mathematical formulation was developed, which is tested by means of computational experiments being performed on illustrative real sized examples.

}, keywords = {closed-loop supply chain, Design and Planning, two-stage stochastic}, doi = {10.1016/B978-0-444-53711-9.50189-9}, url = {http://www.sciencedirect.com/science/article/pii/B9780444537119501899}, author = {Gomes, M. Isabel and Zeballos, Luis J. and Barbosa-Povoa, Ana P. and Novais, Augusto Q.}, editor = {Pistikopoulos, E and Georgiadis, M.C. and Kokossis, A} } @conference {Ramos2011, title = {Restructuring service areas and vehicle routes in a recyclable waste collection system}, booktitle = {EurOMA Conference}, year = {2011}, pages = {1{\textendash}10}, address = {Cambridge, UK}, abstract = {

The present work aims to develop a decision supporting tool to help the decision making process related to the planning of waste collection systems. Such systems involve more than one depot and the objective is to define the delimitation of service areas and the vehicles routes. The problem is modelled as a multi-product, multi-depot vehicle routing problem. A hybrid method that combines exact formulations with heuristic procedures is developed and applied to a real recyclable collection system whose managers want to restructure the current service areas as well as the vehicle routes used to collect three types of recyclable materials.

}, keywords = {multiple depots, service areas, vehicle routing}, attachments = {https://docentes.fct.unl.pt/sites/default/files/mirg/files/2011_ramosgomesbpovoa_euroma.pdf}, author = {Ramos, Tania Rodrigues Pereira and Gomes, Maria Isabel and Barbosa-p{\'o}voa, Ana Paula} } @proceedings {Ramos2011a, title = {Solving a multi-product, multi-depot vehicle routing problem by a hybrid method}, journal = {Livro de actas do 15{\textordmasculine} congresso da APDIO, IO2011}, year = {2011}, pages = {261-273}, address = {Coimbra, Portugal}, abstract = {

This 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.

}, keywords = {hybrid method, multi-depot, multi-product, recyclable, vehicle routing, waste collection system}, attachments = {https://docentes.fct.unl.pt/sites/default/files/mirg/files/2011_ramosgomesbarbosapovoa_io2011.pdf}, author = {Ramos, Tania Rodrigues Pereira and Gomes, Maria Isabel and Barbosa-p{\'o}voa, Ana Paula} } @proceedings {Santana2011, title = {Supply Chain Optimization: Application to a real case}, journal = {Livro de actas do 15{\textordmasculine} congresso da APDIO, IO2011}, year = {2011}, pages = {199-211}, address = {Coimbra, Portugal}, abstract = {

The increase focus of companies in clients{\textquoteright} 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.

}, keywords = {chain modeling, closed loop supply chain, forward supply chain, logistics providers, supply, supply chain integration}, attachments = {https://docentes.fct.unl.pt/sites/default/files/mirg/files/2011_santanagomesbarbosapovoa_io2011.pdf}, author = {Santana, Nuno Miguel and Gomes, Maria Isabel and Barbosa-povoa, Ana Paula} } @article {Gomes20111645, title = {Modelling a recovery network for WEEE: A case study in Portugal}, journal = {Waste Management}, volume = {31}, number = {7}, year = {2011}, note = {n/a}, pages = {1645 - 1660}, abstract = {

The European Union directive for electric and electronic waste, published in 2003, enforced all European countries to meet some targets concerning the recycling and recovery of these products. This directive was transposed to the Portuguese legislation in 2004. Following this, a group of EEE producers set up an organization (Amb3e) whose mission was to design and manage a nationwide recovery network for WEEE, which will be the subject matter of this work. A generic MILP model is proposed to represent this network, which is applied to its design and planning, where the best locations for collection and sorting centres are chosen simultaneously with the definition of a tactical network planning. Several analyses are performed to provide further insights regarding the selection of these alternative locations. The results gave support to the company strategic expansion plans for a high number of centres to be opened and to their location near the major WEEE sources.

}, issn = {0956-053X}, doi = {10.1016/j.wasman.2011.02.023}, url = {http://www.sciencedirect.com/science/article/pii/S0956053X11001085}, author = {Gomes, Maria Isabel and Barbosa-povoa, Ana Paula and Novais, Augusto Q.} } @conference {Ramos2010, title = {A Multi-product, Multi-depot Periodic Vehicle Routing Problem in a Reverse Logistics System}, booktitle = {POMS 21st Annual Conference}, year = {2010}, pages = {1{\textendash}18}, address = {Vancouver, Canada}, abstract = {

n/a

}, attachments = {https://docentes.fct.unl.pt/sites/default/files/mirg/files/2010_ramosgomesbpovoa_poms2010.pdf}, author = {Ramos, Tania and Gomes, Maria I and Barbosa-povoa, Ana Paula} } @inbook {Fernandes2010, title = {The retrofit of a closed-loop distribution network: the case of lead batteries}, booktitle = {Computer Aided Chemical Engineering}, volume = {28}, year = {2010}, note = {

n/a

}, pages = {1213{\textendash}1218}, publisher = {Elsevier}, organization = {Elsevier}, abstract = {

n/a

}, keywords = {closed-loop supply chain, network design, network planning, retrofit}, url = {http://linkinghub.elsevier.com/retrieve/pii/S1570794610282032}, author = {Fernandes, A.S. and Gomes-Salema, M.I. and Barbosa-Povoa, A P} } @article {Salema2010, title = {Simultaneous design and planning of supply chains with reverse flows: A generic modelling framework}, journal = {European Journal of Operational Research}, volume = {203}, number = {2}, year = {2010}, pages = {336{\textendash}349}, publisher = {Elsevier B.V.}, abstract = {

The increase in societal awareness towards environmental issues has accrued the responsibility of goods producers, which at present came to encompass the entire product life cycle. Recently, the efficient design and operation of supply chains with return flows have, in particular, become a major challenge for many companies, given the high number of factors involved and their intricate interactions. In this paper, a multi-period and multi-product network model for the simultaneous design and planning of supply chains with reverse flows is proposed. A graph approach based on the conventional concepts of nodes and arcs is employed to model the network, where it is assumed that any network node is a transformation point of inbound into outbound flows, which in the limit may not differ, and that related arcs describe products flows along the chain. In here the formulation of time adopts a management perspective, i.e., the strategic design of the supply chain is dealt simultaneously with the tactical planning of its operation, which covers supply, production, storage and distribution. An example based on a Portuguese industry case is studied in order to validate both the applicability and adequacy of the model to real world problems.

}, keywords = {closed-loop supply chains}, issn = {0377-2217}, doi = {10.1016/j.ejor.2009.08.002}, url = {http://dx.doi.org/10.1016/j.ejor.2009.08.002}, attachments = {https://docentes.fct.unl.pt/sites/default/files/mirg/files/preprint_2010_salemabarbosapovoanovais_ejor.pdf , https://docentes.fct.unl.pt/sites/default/files/mirg/files/2010_salemabpovoanovais_ejor.pdf}, author = {Salema, Maria Isabel Gomes and Barbosa-povoa, Ana Paula and Novais, Augusto Q.} } @inbook {Gomes-Salema2009a, title = {An Eco-Efficiency Study for a WEEE Recovery Network: The Portuguese Case}, booktitle = {10th International Symposium on Process Systems Engineering}, volume = {27}, year = {2009}, pages = {2073{\textendash}2078}, publisher = {Elsevier}, organization = {Elsevier}, abstract = {

The rapid growth of electric and electronic equipment waste (WEEE) transformed this waste stream into a worldwide problem. The Directive 2002/96/EC on electrical and electronic waste aims at the reduction of the environmental impact of WEEE, encouraging end-of-life management, eco design, life cycle analyses and extended producer responsibility. However, this legislation may not produce the results the legislator aimed for. In this work we analyse the environmental impact of a WEEE recovery network in the Portuguese context. With this aim, a model, previously developed by the authors for the optimal design of this network using economic indicators (Salema, 2007), was now adapted to design the network subjected to the minimization of environmental performance indices. The original mathematical formulation was found to be flexible and easily adapted to the two types of indices and the major differences between the optimal network configurations obtained, were identified and discussed.

}, keywords = {environmental impact, optimization, recovery network}, doi = {10.1016/S1570-7964(09)70736-9}, url = {http://www.sciencedirect.com/science/article/pii/S1570794609707369}, author = {Gomes-Salema, M.I. and Barbosa-Povoa, A. and Novais, A Q}, editor = {Alves, RMB and Nascimento, C.A.O. and Biscaia Jr., E.C.} } @book {Gomes-Salema2009, title = {Livro de Actas do 14{\textordmasculine} Congresso da Associa{\c c}{\~a}o Portuguesa de Investiga{\c c}{\~a}o Operacional, IO2009}, year = {2009}, note = {

n/a

}, address = {Caparica, Portugal}, abstract = {

n/a

}, isbn = {978-989-20-1639-9}, editor = {Gomes-Salema, Maria Isabel and Barbosa-povoa, Ana Paula} } @conference {Ramos2009, title = {A multi-product, multi-depot vehicle routing problem in a reverse logistics system: comparative study of an exact formulation and a heuristic algorithm}, booktitle = {Livro de actas da 14{\textordmasculine} congresso da APDIO, IO2009}, year = {2009}, pages = {195{\textendash}202}, keywords = {heuristic, milp formulation, reverse logistics, vehicle routing problem}, author = {Ramos, Tania Rodrigues Pereira and Gomes-Salema, Maria Isabel and Barbosa-povoa, Ana Paula} } @article {Salema2009, title = {A strategic and tactical model for closed-loop supply chains}, journal = {OR Spectrum}, volume = {31}, number = {3}, year = {2009}, note = {

n/a

}, pages = {573{\textendash}599}, abstract = {

In this paper, a strategic location-allocation model is developed for the simultaneous design of forward and reverse supply chains. Strategic decisions such as network design are accounted for together with tactical decisions, namely, production, storage and distribution planning. The integration between strategic and tactical decisions is achieved by considering two interconnected time scales: a macro and a micro time. At macro level, the supply chain is designed in order to account for the existing demands and returns, whose satisfaction is planned simultaneously at the micro level where tactical decisions are taken. A Mixed Integer Linear Programming formulation is obtained which is solved to optimality using standard Branch \& Bound techniques. Finally, the model accuracy and applicability is illustrated through the resolution of a case study.

}, keywords = {closed-loop supply chain, discrete time, network design, open-loop supply chains}, issn = {0171-6468}, doi = {10.1007/s00291-008-0160-5}, url = {http://www.springerlink.com/index/10.1007/s00291-008-0160-5}, author = {Salema, Maria Isabel Gomes and P{\'o}voa, Ana Paula Barbosa and Novais, Augusto Q.} } @conference {Salema2008a, title = {Analysis and Retrofit of the EEE Portuguese Recovery Network}, booktitle = {POMS 19th Annual Conference}, year = {2008}, address = {LA Jolla, USA}, abstract = {

The Portuguese directive 230/2004 established December 2006 as the dead-line for the legal targets of EEE recovery to be achieved. The EEE producers working in Portugal set up an organization whose mission is to design and manage this recovery network. A MILP model was previously developed to optimize the network design where, by considering EEE sources and recycling facilities locations as known, sorting centre locations were determined together with the planning of collection and sorting activities. In the present paper, the network planned by the Portuguese EEE organization is compared with the results provided by this early model. In addition, and taking into account new organizational objectives, where collecting and sorting entities should independently perform the associated activities, the developed model is further extended, in order to account for a new network level related to the collection and sorting activities, and the previous network is retrofitted.

}, keywords = {EEE, optimization, recovery network, supply chain design}, attachments = {https://docentes.fct.unl.pt/sites/default/files/mirg/files/2008_salema08analysisretrofiteeeportugeserecoverynetwork_poms08.pdf}, author = {Salema, Maria Isabel Gomes and Barbosa-povoa, Ana Paula and Novais, Augusto Q.} } @conference { ISI:000258907700076, title = {Design of a recovery network in Portugal: the electric and electronic equipment case}, booktitle = {IEEE Internationa Engineering Management Conference, Europe}, year = {2008}, pages = {459-463}, type = {{Proceedings Paper}}, address = {Estoril, Portugal}, abstract = {

An European directive established that all EU countries must have, until the end of 2006, a recovery network for the electric and electronic equipment waste (WEEE). In Portugal, a group of producers formed a non-profit organization to design and manage this waste now. In this work, a model developed previously by the authors to design and plan a generic WEEE network is presented and applied to the Portuguese case. The results obtained are discussed and compared with the network that is currently operating.

}, keywords = {electric and electronic equipment, facility location}, optimization model, {recovery network}, isbn = {{978-1-4244-2288-3}}, author = {Salema, Maria Isabel G and Barbosa-Povoa, Ana P. and Novais, Augusto Q.} } @conference {Cunha2008, title = {An Optimization Model for the Design of Closed Loop Supply Chains with Minimum Environmental Impacts}, booktitle = {Computer Aided Chemical Engineering}, year = {2008}, pages = {1{\textendash}6}, abstract = {

In this work, the design of supply chains with reverse flows is studied in a multi-objective context. A MILP model is developed for the optimization of the supply chain structures where both environmental impacts and costs are considered. An optimal Pareto front is obtained that plays an important role in evaluating the best locations of all the entities in the supply chain while accounting for the global supply chain environmental impacts. A study based on a Portuguese glass industry is presented to corroborate both the applicability and the adequacy of the model.

}, keywords = {closed-loop supply chains, design, life cycle assessment, multi-objective}, attachments = {https://docentes.fct.unl.pt/sites/default/files/mirg/files/2008_cunhasalemabarbosapovoanovais08_escape18.pdf}, author = {Cunha, Ana Diniz and Salema, Maria Isabel Gomes and Barbosa-povoa, Ana Paula and Novais, Augusto Q.} } @inbook {Barbosa-povoa2007, title = {Design and Planning of Closed Loop Supply Chains}, booktitle = {Supply Chain Optimization}, year = {2007}, note = {

n/a

}, pages = {187{\textendash}218}, publisher = {Wiley}, organization = {Wiley}, abstract = {

n/a

}, isbn = {3527319069}, author = {Barbosa-povoa, Ana Paula and Salema, Maria Isabel Gomes and Novais, Augusto Q.}, editor = {Papageorgiou, Lazaros G and Georgiadis, Michael C} } @conference {Salema2007a, title = {Design of recovery supply chains: a Portuguese recovery network for WEEE}, booktitle = {Computer Aided Chemical Engineering}, volume = {24}, number = {CD}, year = {2007}, pages = {1{\textendash}6}, abstract = {

All European countries are building structures to support collection and recovery of electric and electronic waste (WEEE). In this work, the study of a Portuguese recovery network is presented. A MILP model is developed in order to determine the best WEEE network structure as well as the associated optimal plan. Several different analyses are performed.

}, keywords = {electric and electronic waste, optimization, supply chain design}, url = {http://www.nt.ntnu.no/users/skoge/prost/proceedings/escape17/papers/T3-159.pdf}, attachments = {https://docentes.fct.unl.pt/sites/default/files/mirg/files/2007_salema07portrecreee_escape17.pdf}, author = {Salema, M.I.G. and Barbosa-P{\'o}voa, A.P. and Novais, A Q and Luizio, M.} } @article {salema2007optimization, title = {An optimization model for the design of a capacitated multi-product reverse logistics network with uncertainty}, journal = {European Journal of Operational Research}, volume = {179}, number = {3}, year = {2007}, pages = {1063{\textendash}1077}, publisher = {Elsevier}, abstract = {

In this work the design of a reverse distribution network is studied. Most of the proposed models on the subject are case based and, for that reason, they lack generality. In this paper we try to overcome this limitation and a generalized model is proposed. It contemplates the design of a generic reverse logistics network where capacity limits, multi-product management and uncertainty on product demands and returns are considered. A mixed integer formulation is developed which is solved using standard B\&B techniques. The model is applied to an illustrative case.

}, url = {http://dx.doi.org/10.1016/j.ejor.2005.05.032}, author = {Salema, Maria Isabel Gomes and Barbosa-povoa, Ana Paula and Novais, Augusto Q.} } @conference {Salema2006b, title = {Supply Chain Design and Planning with Product Return: An Optimization Approach}, booktitle = {Production and Operations Management Society Conference}, year = {2006}, pages = {1{\textendash}11}, address = {Boston, USA}, abstract = {

This 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.

}, keywords = {forward and reverse flows, graph network, milp model, supply chain design}, attachments = {https://docentes.fct.unl.pt/sites/default/files/mirg/files/2006_salema06scdesignplanning_poms06.pdf}, author = {Salema, Maria Isabel Gomes and Barbosa-P{\'o}voa, A.P. and Novais, Augusto Q.} } @article {Salema2006c, title = {A warehouse-based design model for reverse logistics}, journal = {Journal of the Operational Research Society}, volume = {57}, number = {6}, year = {2006}, note = {

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}, pages = {615{\textendash}629}, publisher = {Nature Publishing Group}, abstract = {

In this paper, an MILP formulation is proposed for the design of a reverse logistics network based on a warehouse location{\textendash}allocation model, which optimizes, simultaneously, the forward and reverse networks. A single product model with unlimited capacity is first defined. Subsequently, the model is extended to a multi-product capacitated recovery network model, where capacity limitations and a multi-product system can be considered. The proposed model is compared to published work in the field, where different model assumptions have been proposed. Two cases are described so as to gain a better insight into the model and allow a comparative analysis.

}, keywords = {model performance, optimization, reserve logistics, warehouse location}, doi = {10.1057/palgrave.jors.2602035}, url = {http://www.palgrave-journals.com/jors/journal/v57/n6/abs/2602035a.html}, author = {Salema, MI and P{\'o}voa, APB and Novais, A Q} } @conference {Salema2005a, title = {Design and Planning of Closed-loop Supply Chains: An Optimisation Approach}, booktitle = {ChemPor Conference}, year = {2005}, note = {

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}, month = {21-23 Sept.}, pages = {2{\textendash}7}, address = {Coimbra, Portugal}, abstract = {

A general model for the design and planning of closed-loop supply chains is proposed. The model is both strategic and tactical in nature, containing two levels of decisions: the location of facilities and the planning of production, storage and distribution. Its mathematical formulation is solved using a standard Branch and Bound technique. The model applicability and accuracy are studied on a modified version of an already published case study.

}, keywords = {assembly, disassembly, milp model, optimization, supply chain}, attachments = {https://docentes.fct.unl.pt/sites/default/files/mirg/files/2005_salema05designplanningclsc_chempor05.pdf}, author = {Salema, Maria Isabel G and Barbosa-p{\'o}voa, Ana Paula and Novais, Augusto Q.} } @inbook {Salema2005, title = {Design and planning of supply chains with reverse flows}, booktitle = {Computer Aided Chemical Engineering}, volume = {20}, year = {2005}, note = {

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}, pages = {1075{\textendash}1080}, publisher = {Elsevier}, organization = {Elsevier}, abstract = {

A multi-product model for the design of global supply chains with reverse flows is proposed. Two levels of decisions are considered, one strategic and one tactical. The first is modelled through a macro perspective of time where the determination of the network structure and flows is accomplished. At tactical level, a micro perspective of time is considered, where production planning and inventory management are addressed in detail. A mixed integer linear programming formulation is developed which is solved with standard Branch and Bound techniques. The model accuracy and suitability are studied using a case study.

}, keywords = {optimization, planning, reverse logistics, supply chain design}, url = {http://www.sciencedirect.com/science/article/pii/S1570794605800215}, author = {Salema, M.I.G. and P{\'o}voa, APB and Novais, A Q}, editor = {Puigjaner, Luis and Espu{\~n}a, Ant{\'o}nio} } @conference {Salema2005d, title = {Dynamic network design model with reverse flows}, booktitle = {POMS 16th Annual Conference}, volume = {4643}, number = {003}, year = {2005}, note = {

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}, pages = {19}, address = {Chicago, USA}, abstract = {

Much attention is currently given to the study of supply chains. Most studies are, however, only concerned with forward chains, rendering reverse chains a field insufficiently covered. Few optimization models addressing either the design of reverse networks or the simultaneous design of forward and reverse networks have been presented. We propose a MILP model for the design and planning of an integrated forward and reverse chain. While minimizing cost, the network structure is defined simultaneously with production and storage planning. Dynamic aspects are accounted for using a two-time scale, fully interconnected structure, where at a macro time the network design is performed and at a micro time the planning is optimised. The deterministic model is extended and a scenario approach is applied to account for uncertainties in demand and return of products. A case study is solved and a common structure to all scenarios is obtained, while scenario dependent policies are defined for distribution, production and storage. The model generality is corroborated with good performance results.

}, attachments = {https://docentes.fct.unl.pt/sites/default/files/mirg/files/2005_salema05dynamicnetwrokdesign_poms05.pdf}, author = {Salema, Maria Isabel Gomes and Barbosa-P{\'o}voa, A.P. and Novais, Augusto Q.} } @conference {Salema2005c, title = {Redesigning a global supply chain with reverse flows}, booktitle = {10th International Symposium on Logistics}, number = {2001}, year = {2005}, address = {Lisbon, Portugal}, abstract = {

In recent years much attention has been given to global supply chains. However, the emphasis has been on forward chains, with reverse flows been insufficiently studied. In this work, we study closed loop supply chains and analyse the impact caused by the introduction of new facility sites into an already existing supply chain. The model considers both strategic and tactical decisions allowing for the design of a global supply chain with reverse flows. The impact of the network redesign is analysed and the associated costs calculated. The obtained MILP is solved using a standard Branch and Bound solver. The results obtained prove that the proposed model handles satisfactorily the network redesign problem.

}, keywords = {global supply chain, optimization, retrofit, reverse flows}, attachments = {https://docentes.fct.unl.pt/sites/default/files/mirg/files/2005_salema05redesigningsc_isl05.pdf}, author = {Salema, Maria Isabel Gomes and Barbosa-povoa, Ana Paula and Novais, Augusto Q.} } @conference {Salema2003, title = {A capacitated multi-product reverse logistics network model with uncertainty}, booktitle = {EUROMA/POMS Joint Conference Proceedings}, number = {1993}, year = {2003}, note = {

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}, month = {16-18 Jun}, pages = {1{\textendash}10}, address = {Cernobbio, Italy}, abstract = {

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}, keywords = {global operations and optimisation, reverse logistics}, author = {Salema, Maria Isabel Gomes and Barbosa-p{\'o}voa, Ana Paula and Novais, Augusto Q.} }