Consequence Techniques (Consequence Analysis)

The estimation of loss in the case of an accident.
Consequence analysis is used to estimate the likely impact should the undesired event occur. Consequence analysis should:

    • be based on the undesirable events selected;
    • describe any consequences resulting from the undesirable events;
    • take into consideration existing measures to mitigate the consequences together with all relevant conditions that have an effect on the consequences;
    • give the criteria used for completing the identification of the consequences;
    • consider both immediate consequences and those that may arise after a certain time has elapsed, if this is consistent with the scope of the study;
    • consider secondary consequences, such as those associated with adjacent equipment and systems.
    Consequence analysis involves estimating the impact on people, property or environment, should the undesired event occur. Normally, for risk calculations related to safety (of the public or workers), it consists of estimating the number of people located in different environments, at different distances from the source of the event, that may be either killed, injured or seriously affected, given the undesired event has occurred.
    The undesired events usually comprise situations such as release of toxic materials, fires, explosions, projectiles from disintegrating equipment, etc. Consequence models are needed for predicting the extent of casualties and other effect. The knowledge of the release mechanism and the subsequent fate of the released material (or energy) enables prediction to be made of the effects of the release at any distance from the source at any time.
    There are many methods for estimating such effects ranging from simplified analytical approaches to very complex computer models. Care should be taken to ensure that the methods are appropriate to the problem being considered.
    Reference: IEC 60300-3-9
    Technical Tools/Risk Assessment/Quantitative Risk Assessment