Abstract: The method of root cause analysis looks for the factors that lead to the occurrence of damage or accident in the organization so that it can be prevented from repeating by adopting and implementing the appropriate method And achieved the advantages of RCA method, including reducing costs and increasing the reliability of critical equipment. Although RCA is not a new topic and there are many studies in this field in different fields, But the existing researches have investigated specific examples of failures And the lack of a structured process to implement RCA in the oil industry is visible. The purpose of this research is to develop a solution and a model that can facilitate and systematize the implementation of RCA in oil and gas industries. Therefore, the mentioned model is presented in the form of a flowchart to create a specific structure and framework for the implementation of RCA, so that it can be implemented for any failure in any of the equipment and without creating restrictions on the use of a specific method. In order to achieve this model, the process of root cause analysis and commonly used methods were investigated And finally, an algorithm for performing RCA was presented in such a way that it first checks the necessity of performing RCA in case of any failur and if the implementation of root cause analysis is required, a specific procedure based on the existing standards should be followed and includes the types of methods and the implementation process of each of them so that the appropriate method can be chosen according to the case and based on certain criteria (using the fuzzy TOPSIS method). In this direction and to achieve this goal, previous sources and researches, as well as the opinions of university professors and experts and specialists and industry experts have been used. In order to eva‎luate the proposed algorithm and show how it works, the said model was implemented in Isfahan Oil Refining Company And the effectiveness of the model in using RCA to analyze the defects was well confirmed and satisfied by the refinery experts. In this regard, with the suggestions and advice of relevant experts, three cases of breakdowns that occurred in the refinery were analyzed and investigated, which are: Destruction of turbine compressor blades of gasoline production unit, The burning of the heater element of the air dryer of the water and steam unit, and failure of automatic valves in the new oil extraction unit. Finally, it was concluded that while this algorithm meets the requirements, RCA implementation under this comprehensive approach and with this holistic view can lead to more efficient and accurate decisions. which will ultimately lead to the reduction of costs caused by breakdowns and the improvement of equipment reliability. In one of the above case studies, a solution was proposed and partially implemented (as a pilot) and paid for, and its ineffectiveness was proven. The noteworthy point is that the mentioned solution was not selected and proposed by the model of this research And the experts in the field of Net in the refinery believed that this case is due to the comprehensiveness and overview of the research model, which in a way also implies ensuring the credibility of the model.

مهدي مهنام

مهدي مهنام , علي زينل همداني