AAOM Handbook

Threat Consequence

The potential type and seriousness of the consequences of Threat. These may include; • Safety, • Environment, • Production losses, • Off-specification product, • Cost of damage to plant, and • Customer impact. A standardised 6x6 table of Consequence types and seriousness is used.

Threat Description

A brief description that includes the action and object that will result in a Threat occurring. eg for engine wear it might be coke build-up in oil. For engine corrosion it might be acid build-up in oil.

Threat Exposure Probability

The probability (expressed as a percentage) that a specified consequence will result when a failure occurs – eg there is a 10% probability that a disabling injury will result when the failure occurs.

Threat Mechanism

A Threat Mechanism is the means through which a probable Threat is created/initiated. The OPERATING MODEL categorises the types of Threat Mechanism as; • Design, • Operation, • People, • Environment,

• Commercial, • Natural, and • Social.

Threat Probability Distribution

The shape of the histogram for the probability of occurrence for a Threat over the time. Probability distributions are generalised into three basic components in the OPERATING MODEL; Running In (decreasing over time), Random (constant over time), or Age Related (increasing over time). These one, or combination of, these three components may represent the probability of a threat.

© McAlear Management Consultants 2004

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