Händelseträdsanalys

Händelseträdsanalys, often translated as Event Tree Analysis (ETA), is a graphical, inductive method used to analyze the potential consequences of an initiating event. It starts with a specific event, such as equipment failure or human error, and then systematically traces the possible sequences of subsequent events that could occur. These subsequent events are typically safety systems or barriers that are intended to prevent or mitigate the consequences of the initial event.

The analysis branches out at each point where a safety system can either succeed or fail. This creates a tree-like structure where each path from the initiating event to the end represents a unique sequence of system successes and failures. The probability of each path is calculated by multiplying the probabilities of the individual events along that path. By summing the probabilities of all the paths leading to undesirable outcomes, the overall probability of a specific consequence can be determined.

Händelseträdsanalys is valuable for identifying critical safety systems, understanding failure modes, and quantifying risks. It is commonly employed in safety-critical industries like nuclear power, chemical processing, and aerospace to assess the safety of complex systems and identify areas for improvement. The method provides a structured way to think about accident scenarios and their likelihood, aiding in decision-making regarding risk reduction strategies.