Identification and Prioritization of the Criteria Affecting the Performance of the Permit-to-Work System in an Oil Refinery using a Fuzzy Delphi Method and Fuzzy Analytical Hierarchy Process

Background and Objective: Permit-to-work system is a formal, documented, and written system aiming at controlling the risk of occupations that are considered potentially dangerous. This study aimed to identify and prioritize the criteria affecting the performance of the permit-to-work system in an oil refinery. Materials and Methods: The present study was designed and implemented in three steps. In the first step, the primary research criteria were identified after reviewing previous studies and conducting interviews with experts. In the second step, the Fuzzy Delphi method was used to determine the final criteria after obtaining the opinions of 25 experts regarding the primary criteria. Finally, the fuzzy hierarchical analysis method was utilized to weigh and prioritize the identified criteria. Results: The result of the Fuzzy Delphi method showed that six criteria affected the performance of the permit-to-work system. These criteria included the hazard identification and risk assessment, training and competence of individuals, preventive actions, communication, responsibility, and coordination. The prioritization of these criteria using fuzzy hierarchical analysis showed that responsibility )final weight 0.191), as well as coordination and communication (final weight 0.134( obtained the highest and lowest importance among the identified criteria, respectively. Conclusion: In this study, a model of decision-making based on Delphi methods and fuzzy hierarchical analysis was introduced to identify the factors affecting the performance of the permit-to-work system in an oil refinery.