Innovation Driven by Human and Organizational Factors (HOF) in Risk Assessment Methodologies and Standards: ATEX (Explosive Atmosphere) Risk Assessment Application

Abstract

ATEX (explosive atmosphere) risk assessment is required when any equipment or system potentially causes explosive atmospheres. Despite many operations on plant and equipment containing dangerous substances are performed by operators, influences of human and organizational factor (HOF) are mostly neglected. This research work, according to the overview of the general risk assessment and human factor integration techniques, focuses on the HOF influence on a specific application domain: the ATEX (explosive atmosphere) risk assessment domain. The integrated ATEX risk assessment methodology with HOF is proposed. The ATEX-HOF methodology provides a quantitative risk analysis approach with taking into account of HOF. Inside each phase, clearly assessment goals are identified which are enable to conduct the ATEX risk assessment with simplified ‘step-by-step'. An event tree based probabilistic assessment has been introduced, which is taking into account both the technical barrier failure (Prtbf) and the human intervention (e.g. operational failure, and/or operational barrier failure) in terms of Human Error Probability (HEP). Hence, the ATEX-HOF risk assessment becomes more complete than the traditional approach. Two on-site applications shown how taking into account HOFs is particular important in companies where the safety culture is lower and consequently the usual hypothesis of the correctness of operator intervention (in maintenance, normal operations, and emergency) could bring to not conservative results. The applied operational (HOF) barriers explicated in the analysis can be used to support for defining a more detailed set of operational procedures, which is able to maintain the risk level evaluated. In addition, since several accident investigations have found that 80% correspond to human error, in nowadays, the change in safety has focused on developing good safety cultures that positively influence human behaviour at work to reduce errors and violations. HOF as the major consideration within the safety culture plays an important role in the Safety Management System (SMS). Safety culture is not a difficult idea, but it is generally considered as trust, values and attitudes, which is difficult to clarify the meaning in practise. The Event tree based probabilistic assessment method has been introduced to quantify the HOF influence. This research, hence, can be concerned as an attempt to handle safety cultures in practice via the integration of the risk assessment