Developing Accident Scenarios and Initiating Events

you need to identify the accident scenarios of concern and the initiating events that lead to that accident scenario. An initiating event is an event that triggers departure from the normal (preplanned) operations and desired mission. 

Accident scenarios are identified through the safety analysis tools presented in Chapters 5 through 9. It is particularly important that this step be performed well. If inappropriate accident scenarios are developed, then the risk assessment is pointless since you will not have first identified what is important. 

A HAZOP can be used in lieu of a hazard analysis. It is important to apply a safety technique that is fairly comprehensive in identifying hazards and their causes. 

Once the hazard scenarios have been identified, you will need to understand how those hazards came about. If the hazard analysis is not sufficient to understand the underlying causes of the hazard scenario, then further analysis will be necessary. A fault tree is particularly useful because it gives a good sequence of events that lead 

System Safety Engineering and Risk Assessment A Practical Approach 

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