Identification, analyzing and management of human errors in the filter man job using SHERPA method: A case study of an oil refinery

Introduction: Nowadays, despite sensitive and complex technologies, Human Error is of great importance in many work environments due to its unfortunate consequences. For this reason, to limit the impacts of human error, it is necessary to identify and find the causes. Method: The present research was a descriptive-analytic study performed in 2021. After collecting information using the task observation method and interviewing safety officials, unit supervisors, and operators, 16 critical tasks were determined. Then, hierarchical task analysis (HTA) was performed, and human errors in each critical task were identified by the SHERPA method. Results: By analyzing SHERPA worksheets, 181 human errors were identified. Of these, 154 errors (85%) were of performance type, 24 errors (13%) were visited errors, two errors (1%) were related to communication, and 1 error (1%) was selected. Also, according to the results of the risk assessment, 45 errors (25 %) were unacceptable, 20 errors (11 %) were at an adverse risk level, 81 errors (45 %) were acceptable but needed to reconsider, and 35 errors (19 %) were acceptable without needing to review. Conclusion: The most obvious errors that occur in the filtration unit of this refinery were related to functional errors. To reduce the occurrence of the detected error, control solutions such as installing an online monitoring system and alarm on the filtration process, the output of wet-dry solvent pumps, and the vacuum pump were presented