طراحی زنجیره تامین پایدار تحت طرح انتشار تجارت

Increase in environmental concerns together with legislations are forcing industries to take a fresh look at the impact of their supply chain operations on the environment. This paper introduces a mixed-integer linear programming based framework for sustainable supply chain design that considers life cycle assessment (LCA) principles in addition to the traditional material balance constraints at each node in the supply chain. Indeed, the framework distinguishes between solid and liquid wastes, as well as gaseous emissions due to various production processes and transportation systems. The framework is used to evaluate the tradeoffs between economic and environmental objectives under various cost and operating strategies in the aluminum industry. The results suggest that current legislation and Emission Trading Schemes (ETS) must be strengthened and harmonized at the global level in order to drive a meaningful environmental strategy. Moreover, the model demonstrates that efficient carbon management strategies will help decision makers to achieve sustainability objectives in a cost-effective manner.

Supply chain network design attempts to define the best supply chain configuration that enables an organization to maximize its long-term economic performance. Typically, the decisions cover two planning levels: (1) strategic decisions on sourcing, production (opening or closing of facilities), distribution and sales; (2) tactical decisions on supply network planning affecting the flow of goods trough the network. Flexibility, robustness, and responsiveness are some of the strategies that have been used to adapt to dynamic changes in the supply chain environment (Sabri and Beamon, 2000). But, unfortunately the pursuit of short term profitability is still recognized as the one of the major drivers for managerial decisions and this, among other things, has contributed to the slowdown in the current global economy. Nowadays, given the constraints relative to the availability of non-renewable resources (metal, oil, etc.), enterprises are more than ever obliged to rethink their strategies to ensure the sustainability of their operations. Closed-loop supply chains are one of the options that are being considered (Lieckens and Vandaele, 2007, Barker and Zabinsky, 2008, Srivastava, 2008 and Pochampally and Nukala, 2009). Other avenues being studied include different actions related to one or more phases of the product life cycle such as product design (Hugo and Pistikopoulos, 2005), production planning and control for remanufacturing (Jayaraman and Guide, 1999 and Luo and Zhou, 2001), inventory management (Ferretti et al., 2007), product recovery (Jayaraman, 2006), reverse logistics (Sheu and Chou, 2005 and Sheu, 2008) and carbon emissions reduction (Ramudhin et al., 2008). However, these actions may not be enough to guarantee long-term sustainability. Indeed, recovery of used products and re-processing (remanufacturing, recycling, disposal, incineration, etc.) might not only increase operating costs but also contribute to an increase in greenhouse gases (GHG) emissions which defeats long-term stainability. Sustainable development recognizes the interdependence between three dimensions: the economic, the environmental, and the social performances of an organization. An integrated approach that links supply chain decisions to the three pillars of sustainability is advocated. Sustainable supply chain design (Frota Neto et al., 2008) is a new emerging approach that arose in response to this situation and tries to embed economic, environmental as well as societal decisions in supply chains at design time. The objective of the methodology proposed in this paper is to present a formal decision model that considers the important dimensions of sustainability throughout the supply chain life cycle.

In this article, we present a generic mathematical model to assist decision makers in designing sustainable supply chains over their entire life cycle. First, the model has the potential to be a tool that facilitates the understanding of optimal supply chain strate- gies under different environmental policies: recycling and GHG emissions reduction. The model shows that the various environ- mental legislations must be strengthened and harmonized at a global level in order to drive a meaningful long-term environ- mental strategy. Theexplicitconsiderationofenvironmentalcostswithinsupply chain design is critical under the emergence of emission trading schemes. The integration of Life Cycle Analysis principles at the supplychaindesignphasemaximizesthelong-termsustainability. While some specific values of model’s parameters would depend upon the application, the methodology presented here is general enough and may be applied to other supply chain studies to evaluate their performance in term of cost and carbon emissions. Finally, although only the economic and environmental dimen- sions of sustainability are considered in the mathematical model, the methodology can integrate the social dimension as soon as measures of social stainability are identified.