Re-assessment of Aviation Risk Safety Barriers Using Stochastic and Lexical Uncertainty

Results of many investigations and statistical data indicate that aircraft accidents are an iceberg phenomenon for understanding the gap among traffic management, operations, and aviation systems. Although the regulator has established a safety barrier as a defense mechanism against hazards, many accidents and incidents continue to occur. Instead of conducting a comprehensive assessment of an accident/incident prevention system, evaluator conducted a common audit investigation to determine the causal and contributing factors of accident. Current problems of concern in aviation safety management involve a series of constraints, evaluation methods, and complex decision-making processes. Uncertainty in these problems adds complexity. Uncertainty has characteristics such as randomness or vagueness, in nature, both might occur concurrently. Probability is a method of calculating the randomness characteristic of stochastic uncertainty and fuzzy logic is a widely used method of determining a vagueness of lexical uncertainty. The combination of these two methods capable of producing integrated models in both types of uncertainty exists simultaneously. The new safety barrier after recalculation is used by describing it in a related fuzzy set accompanied by its degree of membership. This provides clearer guidance for decision-makers to formulate policies based on the conditions experienced, informed by the history of previous events.