Abstract Today's world is more competitive than ever, and industry increasingly looks to supply chain management as a competitive weapon. the objective of this research is to suggest an integrated approach for Closed Loop Supply Chain network including two phases. In the first phase, a framework for supplier selection criteria in RL is proposed. Beside a fuzzy method is utilized to evaluate suppliers based on quantitative and qualitative criteria. The output of this stage is the weight of each supplier according to each part.in the second phase, we propose a Multi Objctive mixd-integer linear programming model to determine weight of suppliers and amount of item for purching from them(strategic decisions), as well as weight of remanufacturing subcontractor and dedicate product to them (tactical decisions), and find out the optimal number of part and products in CLSC network(operational decisions). The objective functions maximize profit of selling, minimize factory cost as well as cost of unsatisfied demand and rest of them maximize weight of suppliers and allocate return product between recoverable centers in factory and remanufacturing subcontractors. the mathematical programming model is validated through numerical analysis.

Abstract Over the last few decades, reliability engineering has been successfully applied in many industries to improve the performance of equipment maintenance management. Many optimization models and researches are developed and widely used to achieve a high level of maintenance, i.e. the balance of performance, risk, resources, and cost to achieve an optimal solution. although, the application of these techniques to medical equipment is very new,One of the major challenges is how to improve the safety, security and reliability of medical devices. In this paper a FMEA based assessment model is proposed to improve human reliability in medical devices. Fuzzy linguistic variables are used to express the experts’ evaluation for risk factors of sub systems. The results indicate that the human reliability assessment of medical devices must be more focused on reducing soft failures and hidden risks. Also through the designing and developing processes of medical devices, attention must be paid to the communication between operators and designers.

Abstract Every project has many risks and as there are many complexities in projects today, recognizing the most important risks is essential for projects' success and efficiency. In this research, we tried to determine most significant risk's categories in the framework of risk breakdown structure of 4th edition of Project Management Body of Knowledge Guide that can be generalize to all projects in Iran. With considering dependencies and interactive relations between risks of project, we used DEMATEL method to determine the most significant project risk's categories on the basis of risk breakdown structure of 4th edition of Project Management Body of Knowledge Guide. Also fuzzy set theory was applied to measure experts' subjective judgments, experts who have rich expertise and knowledge in Iranian projects were selected to evaluate the influences. The results revealed that "External", "Technical", "Project Management" and "Organizational" risks are significant and in the most important risk's category which is "External", "Regulatory" risks and in "Technical", "Project Management" and "Organizational" risks, "Technology", "Estimating" and "Project Dependencies" are the most important risks respectively and should be paid more attention because they were in the first rank of importance.