of output lines, depending on whether the pivotal event occurs (Yes output) or otherwise (No output). The same applies in the case of conditions where Yes means the condition is satisfied and No means the opposite.
An event sequence diagram, therefore, is a visual representation of a set of possible risk scenarios originating from an initiating event. Each scenario consists of a unique sequence of occurrences and non-occurrences of pivotal events (Point B or C in Figure F-1). Each scenario eventually leads to an end state, which designates the severity of the outcome of that scenario.