TABLE OF CONTENTS "It is easy to dodge our responsibilities but we cannot dodge the consequences of dodging our responsibilities."
Lord Stamp of Shortlands
An important aspect of risk management following hazard identification is the task of consequence analysis. Hazards and operational problems often lead to the release of energy and hazardous materials. What is of importance is the knowledge of "how big?" or "what impact?" will flow from hazardous events. This is the area of consequence analysis and there are several key issues that are discussed in this chapter as a prelude to the more detailed discussion in Chapters 6 and 7. What will be evident from these discussions is that current practice relies heavily on the use of mathematical models to predict a range of physical effects as well as potential impacts on vulnerable receptors.
In discussing consequence analysis it is helpful to clearly distinguish between individual events, incidents and scenarios. We adopt the following conventions in this book:
| event: | a single action or outcome from a system failure |
| incident: | a chain of related events with an initiating event and a termination event. |
| scenario: | a collection of one or more incidents related to a risk analysis investigation |
This is a single action or outcome which characterizes a failure and potentially its subsequent propagation. What is important is the view that each event is a system with its own inputs, outputs, states and parameters as seen in Figure 5-1.
