http://repub.eur.nl/res/aut/4526/ List of Publications en http://repub.eur.nl/static-eur/img/logo.png http://repub.eur.nl http://repub.eur.nl/res/pub/19884/ 2010-01-01T00:00:00Z The primary objective of closed-loop supply chains (CLSC) is to improve the maximum economic benefit from end-of-use products. Nevertheless, the literature within this stream of research advocates that closing the loop also helps to mitigate the undesirable environmental footprint of supply chains. Therefore, closed-loop supply chains are assumed to be sustainable supply chains almost by definition. In this paper we analyse if and when this assumption holds. We illustrate our findings based on the Electric and Electronic Equipment (EEE) supply chain. For all phases of the supply chain, i.e. manufacturing, usage, transportation and end-of-life activities, we assess the magnitude of the environmental impacts, based on a single environmental metric, namely the Cumulative Energy Demand (CED). Given the environmental hot-spots in the Electric and Electronic Equipment supply chain, we propose useful extensions for existing CLSC optimisation models to ensure that closed-loop supply chains are at the same time sustainable supply chains. http://repub.eur.nl/res/pub/15912/ 2009-05-11T00:00:00Z Remanufacturing has long been perceived as an environmentally-friendly initiative. The question of how remanufacturing moderates the relation between environmental impact and economic returns is still unanswered, however. In this paper, we focus our attention on the electronics industry. In particular, we take a close look at remanufacturing within the mobile and personal computers industries. We analyze whether remanufacturing for such products substantially mitigates the energy used in the life-cycle of these products, or whether as in most electrical equipments, it can only marginally contribute to such reduction. Using both process-based and economic input-output data, we show that remanufacturing significantly reduces total energy consumption. Furthermore, we test the ubiquitous hypothesis that the market of remanufactured products is composed by products that have been downgraded and are therefore sold for prices below the average price of the new equipments. Using data from 9,900 real transactions obtained from eBay, we show that this assumption is true for personal computers, but not for mobiles. More importantly, despite the fact that remanufactured products may suffer downgrading, and that consumers therefore command a high discount for them, the economic output per energy unit used is still higher for remanufactured products. We thus conclude that remanufacturing for these two products is not only environmentally friendly, but also eco-efficient. http://repub.eur.nl/res/pub/14785/ 2008-12-04T00:00:00Z Hundreds of millions of electrical and electronic appliances are manufactured every year. Furthermore, it is expected that this number will not substantially decrease in the near future. These equipments have a significant impact on the environment, and ceteris paribus, such environmental impact increases with the number of appliances manufactured. Consumers, NGOs and Governments have acknowledged the potential threat posed by these electrical and electronic products. They have systematically demanded companies to reduce the environmental impact caused be their products and services. Companies have responded to these pressures and have engaged in a number of environmentally friendly initiatives. This thesis is motivated by the task of reducing the environmental impact caused by the myriad of electrical and electronic products that make our lives more conformable and enjoyable. More specifically, it addresses the challenge of efficiently and effectively mitigating such impacts. We show that companies will need a mixture of strategies to respond to this challenge. Furthermore, we show that these strategies must consider environmental, technical and marketing aspects of the business of electrical and electronic products. These three aspects need to be considered systemically, and the solutions will vary greatly according to the companies, the products they manufacture, and the ways in which their supply chains are organized. http://repub.eur.nl/res/pub/13639/ 2008-03-16T00:00:00Z Recent literature on sustainable logistics networks points to two important questions: (i) How to spot the preferred solution(s) balancing environmental and business concerns? (ii) How to improve the understanding of the trade-offs between these two dimensions? We posit that a visual exploration of the efficient frontier and trade-offs between profitability and environmental impacts are particularly suitable to answer these two questions. The visual representation of the efficient frontier, however, presents two challenges. The first is to obtain a good approximation for such frontier without enumerating all extreme efficient solutions. The second is to obtain a good visual representation of the efficient frontier. We propose a two-phased heuristic to handle these two problems. The algorithm is designed for the multi-objective linear problem with three objectives: minimize costs, cumulative energy demand and waste in a reverse logistics network. We illustrate our approach by designing a complex recycling logistics network in Germany. http://repub.eur.nl/res/pub/10176/ 2007-05-11T00:00:00Z The primary objective of closed-loop supply chains (CLSC) is to reap the maximum economic benefit from end-of-use products. Nevertheless, literature within this stream of research advocates that closing the loop helps to mitigate the undesirable footprint of supply chains. In this paper we assess the magnitude of such environmental gains for Electric and Electronic Equipments (EEE), based on a single environmental metric of Cumulative Energy Demand. We detail our analysis for the different phases of the CLSC, i.e. manufacturing, usage, transportation and end-of-life activities. According to our literature review, within the same group of EEE, results greatly vary. Furthermore, based on the environmental hot-spots, we propose extensions of the existing CLSC models to incorporate the CED. http://repub.eur.nl/res/pub/10177/ 2007-05-11T00:00:00Z Recent literature on sustainable logistics networks points to two important questions: (i) How to spot the preferred solution(s) balancing environmental and business concerns? (ii) How to improve the understanding of the trade-offs between these two dimensions? We posit that a complete exploration of the efficient frontier and trade-offs between profitability and environmental impacts are particularly suitable to answer these two questions. In order to deal with the exponential number of basic efficient points in the frontier, we propose a formulation that performs in exponential time for the number of objective functions only. We illustrate our findings by designing a complex recycling logistics network in Germany. http://repub.eur.nl/res/pub/8987/ 2006-10-20T00:00:00Z Recent literature on sustainable logistics networks points to two important questions: (i) How to spot the preferred solution(s) balancing environmental and business concerns? (ii) How to improve the understanding of the trade-offs between these two dimensions? We posit that a complete exploration of the efficient frontier and trade-offs between profitability and environmental impacts are particularly suitable to answer these two questions. In order to deal with the exponential number of basic efficient points in the frontier, we propose a formulation that performs in exponential time for the number of objective functions only. We illustrate our findings by designing a complex recycling logistics network in Germany. http://repub.eur.nl/res/pub/7320/ 2006-02-01T00:00:00Z The objective in this paper is to shed light into the design of logistic networks balancing profit and the environment. More specifically we intend to i) determine the main factors influencing environmental performance and costs in logistic networks ii) present a comprehensive framework and mathematical formulation, based on multiobjective programming, integrating all relevant variables in order to explore efficient logistic network configurations iii) present the expected computational results of such formulation and iv) introduce a technique to evaluate the efficiency of existing logistic networks.The European Pulp and Paper Industry will be used to illustrate our findings.