Investigation of Root Cause of Work-related Accidents in a Vehicle Manufacturing Company Using Tripod-Beta Method

Introduction: Occupational accidents are one of the major challenges of the industrial workplaces. The identifying of the effective causes of the incidents occurrence, could be used to prevent them. This study was aimed to determine basic causes of occupational accidents in a vehicle manufacturing company. Material and Methods: The occupational accidents leading to loss of time, which cause losing at least one working day, occurred from 2012 to 2017 were analyzed using the Tripod-Beta method and the causes of their occurrences were determined from the active failures to the root causes. The data were analyzed using the SPSS-22 software. Results: Eighty percent of the occupational accidents that occurred in a vehicle manufacturing company were related to 6 root causes, i.e. the weakness of OR (20%), EC (17%), MM¬ (12%), CO (10%), IG (10%) and DE (9%). Absence of necessary authority to stop working is the most important reason for the occurrence of the weakness of Organization system with a rate of 28%. Conclusion: By handling three root causes appropriately, i.e. improving OR, EC and MM, more than 50% of accidents can be prevented. Proper hiring of workers, exact definition of accountability and an accurate job description to the employees, proper monitoring and supervision, and near-miss recordings are suggested to reduce this incidence rate.