Methodology for quantitatively monitoring the basic risk factors of accidents: A case study on manufacturing companies

BACKGROUND: Considering that the frequency of a factor contribution to accidents occurrence is not always a reason for the importance of that factor, in addition to studying the participation of basic risk factors (BRFs) in the occurrence of the accidents, their importance must be investigated. OBJECTIVE: The purpose of the present study is to propose a quantitative methodology for monitoring BRFs based on Tripod Beta and Tripod Delta methods. METHODS: In the present study, first, the accidents that took place in the manufacturing companies were analyzed using a reactive approach, ie Tripod Beta. In the second step, a proactive, ie Tripod Delta was used to identify the weaknesses in the companies using safety performance indicators. Finally, a quantitative methodology for monitoring BRFs was proposed. RESULTS: According to the results of the accident analysis, training with 33 cases, hardware with 30 cases, procedures with 25 cases and error induce conditions with 14 cases were the most frequent contributing basic risk factors to the accidents. The lowest score of the basic risk factor indicators was related to the organization (4.9), design (8.8), training (8.3), procedures (8.3), and hardware (8.7). Based on the results, maintenance management, hardware, and training have the highest weight in the occurrence of accidents, 0.23, 0.179, and 0.125, respectively. CONCLUSIONS: he proposed methodology helps the organization to continuously improve safety performance by identifying system’s weaknesses before the accident and invest optimally in the system’s critical points.

Application and modification of the Tripod Beta method for analyzing the causes of oil and gas industry accidents

Background. Understanding the causes of accidents plays a major role in learning from accidents and developing accident prevention and control strategies. Objective. This study aimed at application and modification of the Tripod Beta method for analyzing accident causes in the oil and gas industries. Materials and methods. A total of 68 accidents occurring in the oil and gas industries during 2005-2016 were analyzed. For this purpose, we used the Tripod Beta method and modified it using Reason's Swiss cheese model and analysis accident results. Results. The main causes that have been ignored in the Tripod Beta method were supervision factors involved in 66% of the accidents (underlying causes) and unsafe conditions that contributed to 55% of accidents (immediate causes). The former was incorporated as a sublayer of the underlying cause and the latter as a sublayer of immediate cause to the modified Tripod Beta method. Conclusions. The results of the present study added to the knowledge on the causes of accidents. These results can help increase the capabilities of the Tripod Beta method for analyzing accident causes, such as supervision factors and unsafe conditions, which have been ignored in analyses performed using the Tripod Beta method.