11,778 research outputs found

    Disposition Choices Based on Energy Footprints instead of Recovery Quota

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    This paper addresses the impact of disposition choices on the energy use of closed-loop supply chains. In a life cycle perspective, energy used in the forward chain which is locked up in the product is recaptured in recovery. High quality recovery replaces virgin production and thereby saves energy. This so called substitution effect is often ignored. Governments worldwide implement Extended Producer Responsibility (EPR). Policies are based on recovery quota and not effective from an energy point of view. This in turn leads to unnecessary emissions of amongst others CO2. This research evaluates current EPR policies and presents six policy alternatives from an energy standpoint. The Pareto-frontier model used is generic and can be applied to other closed loops supply chains under EPR, exploiting the substitution effect. The measures modeled are applied to five WEEE cases. We discuss results, pros an cons of various alternatives and complementary measures that might be taken.extended producer responsibility;disposition;energy perspective;substitution effect;government policies;Pareto efficiency

    Design of Closed Loop Supply Chains

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    Increased concern for the environment has lead to new techniques to design products and supply chains that are both economically and ecologically feasible. This paper deals with the product - and corresponding supply chain design for a refrigerator. Literature study shows that there are many models to support product design and logistics separately, but not in an integrated way. In our research we develop quantitative modelling to support an optimal design structure of a product, i.e. modularity, repairability, recyclability, as well as the optimal locations and goods flows allocation in the logistics system. Environmental impacts are measured by energy and waste. Economic costs are modelled as linear functions of volumes with a fixed set-up component for facilities. We apply this model using real life R&D data of a Japanese consumer electronics company. The model is run for different scenarios using different parameter settings such as centralised versus decentralised logistics, alternative product designs, varying return quality and quantity, and potential environmental legislation based on producer responsibility.supply chain management;reverse logistics;facility location;network design;product design

    Collector Managed Inventory, A Proactive Planning Approach to the Collection of Liquids coming from End-of-life Vehicles

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    In this article we introduce Collector Managed Inventory (CMI) as the reverse logistics counter part of Vendor Managed Inventory (VMI).The collection company takes responsibility for the inventories of cores or materials to be recycled.Experience in forward supply chain management has shown the potential of VMI by bringing the coordination of transportation and inventory decisions to the same supply chain entity.Using information technology called telemetry, we are able to monitor inventory levels at distance.We introduce a proactive planning methodology based on two types of collection orders: must- and can-orders.Every collection period all must-orders have to be collected, while canorders are only collected if they can be combined beneficially with the must-orders.The routing problem is solved by a combination of route generation and set partitioning.The system is illustrated in a real-life case study for Auto Recycling Nederland on the collection of liquids coming from end-oflife vehicles, such as coolant and oil.In several scenarios the old reactive approach is compared to the proactive approach resulting in cost savings up to about 19%.supply;logistics;vehicle routine;distribution;information technology;inventory

    Design of Closed Loop Supply Chains

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    Increased concern for the environment has lead to new techniques to design products and supply chains that are both economically and ecologically feasible. This paper deals with the product - and corresponding supply chain design for a refrigerator. Literature study shows that there are many models to support product design and logistics separately, but not in an integrated way. In our research we develop quantitative modelling to support an optimal design structure of a product, i.e. modularity, repairability, recyclability, as well as the optimal locations and goods flows allocation in the logistics system. Environmental impacts are

    The System Dynamics Model in Electronic Products Closed-Loop Supply Chain Distribution Network with Three-Way Recovery and the Old-for-New Policy

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    With the technological developments and rapid changes in demand pattern, diverse varieties of electronic products are entering into the market with reduced lifecycle which leads to the environmental problems. The awareness of electronic products take-back and recovery has been increasing in electronic products supply chains. In this paper, we build a system dynamics model for electronic products closed-loop supply chain distribution network with the old-for-new policy and three electronic products recovery ways, namely, electronic products remanufacturing, electronic component reuse and remanufacturing, and electronic raw material recovery. In the simulation study, we investigate the significance of various factors including the old-for-new policy, collection and remanufacturing, their interactions and the type of their impact on bullwhip, and profitability through sensitivity analysis. Our results instruct that the old-for-new policy and three electronic products recovery ways can reduce the bullwhip effect in the retailers and the distributors and increases the profitability in the closed-loop supply chain distribution network

    A Methodology for Assessing Eco-efficiency in Logistics Networks

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    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.Eco-efficiency;Environmental impacts;Profitability;Recycling logistics network

    Optimization modeling for the operation of closed-loop supply chains.

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    Environmentally conscious manufacturing and remanufacturing/recycling of endof- life products are steadily growing in importance. The problem of managing the waste generated due to the disposal of many types of products has many aspects. The main driving forces for solving this growing problem are the rapid diminishment of raw material resources, decreasing space in landfills and increasing levels of pollution. The drivers associated with these forces are governmental regulations which require that the manufacturers take back the end-of-life products and customer perspectives on environmental issues. This research considers the problem of increasing levels of electronic and electrical equipments waste. The implementation of closed-loop supply chains can be beneficial both economically and ecologically for these problems. Relevant literature to understand various issues involved in the operation of reverse logistics systems and closed-loop supply chains is reviewed. Upon reviewing the issues involved in closed-loop supply chains, the problem is considered as an ill-structured problem. A problem structuring technique called Why-What\u27s Stopping Analysis is used to analyze the problem from various perspectives. Also, since a closed-loop supply chain involves multiple objectives, two techniques for categorizing the objectives into fundamental and means objectives are presented: Fundamental Objective Hierarchy and Means Objective Network techniques, respectively. A Goal Program (GP) modeling approach is used to handle many of the objectives identified by the previously mentioned techniques. In this research a consolidated objective function is defined which includes all of the deviational variables considered in various goals defined in the model. The consolidated goal is to minimize the weighted sum of all deviational variables. A non preemptive goal programming approach has been used with goals being assigned different weights according to their priorities. The values of the deviational variables help the decision maker to see which of the different goals are satisfied with the existing values of parameters and which of the goals aren\u27t. The goal program has been run with both uniform and variable demand values in all the periods. In the absence of real data, all the parameter values considered for this research have been assumed. The major contributions of the research are as follows: each member of the supply chain has its own individual objective and the related constraints which is a more realistic approach, the model considers multiple products, and the model considers operations at the product, subassembly, part, and material levels. All the above contributions make this research as the first approach of its kind which has never been attempted (based on literature reviewed) and the goal programming methodology used is also a well accepted approach among all the multi-objective programming approaches. Results show the effect of varying the priority/weight associated with a goal. Results also show that values of the deviational variables (positive or negative) help a decision maker to analyze the model. The goal programming approach is considered to be the most effective approach in terms of defining the mathematical model, analyzing the output, and modifying the model (if needed)

    Designing and Evaluating Sustainable Logistics Networks

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    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.Eco-efficiency;Data Envelopment Analysis (DEA);Multi-Objective Programming (MOP);Supply Chain Design;Sustainable Supply Chain
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