Risk Assessment using Fuzzy FMEA (Case Study: Tehran Subway Tunneling Operations)

Background/Objective: FMEA is an appropriate tool for identification, evaluation and effective management of risks in a project. For this purpose, the proposed work tried to assess the risks by using a fuzzy FMEA. Methods: On the one hand, the parameter input of the method (frequency, occurrence, severity and detection of a failure mode) is determined by experts and can be found in difficult due to several uncertainties as well as qualitative and subjective judgments. Results: On the other hand, tunnel construction projects are found among the riskiest projects due to lack of sufficient knowledge of land characteristics, surrounding conditions, diversity of activities, expansion, equipment density, human factors and uncertainties related to their design and implementation. Failure in identification, evaluation, timely and effective management of these projects can increase the duration and cost of implementing these projects. In this study, fuzzy logic (using two computational approaches) is used as a complementary tool to perform a consistent and logical analysis. Conclusion: The results showed that Fuzzy FMEA is more flexible and realistic compared with the traditional FMEA method.