Chekoubi, Zakaria <br/><br/>
Front matter 

 -  2025.<br/>							 
<br/><br/> 91 
<br/><br/> The transition to sustainable supply chains has become imperative in response to the global climate crisis. This study proposes an integrated model for sustainable supply chains based on the closed-loop concept, emphasizing the principles of material reduction, reuse, and recycling. To assess its effectiveness, the Material Circularity Indicator (MCI) is incorporated, providing a precise evaluation of material circularity and product sustainability throughout the lifecycle. The proposed model offers several significant environmental benefits, including reduced ecological impact through optimized recycling and reuse processes, minimized waste and resource extraction, and lowered carbon emissions. Economically, implementing a closed-loop supply chain reduces raw material purchases and waste management costs, resulting in long-term financial benefits. Furthermore, digital technologies such as FlexSim, AnyLogix, and Simul8 play a central role in optimizing these processes. These tools enable the simulation and design of more efficient supply chains, thereby enhancing business profitability. Finally, although many companies are adopting the closed-loop model, uncertainties remain regarding its practical implementation and the assessment of product sustainability. The MCI helps address these challenges by providing a reliable method to measure material circularity and assess their contribution to a sustainable supply chain model. In summary, this research presents an innovative approach that integrates the closed-loop system, MCI, and digital solutions to create more responsible, efficient, and sustainable supply chains, while reducing costs and optimizing resources.