Single
Loss Expectancy (SLE) represents an organization’s loss from a single threat. Which of the following
formulas best describes the Single Loss Expectancy (SLE)?
A.
SLE = Asset Value (AV) * Exposure Factor (EF)
B.
SLE = Asset Value (AV) * Annualized Rate of Occurrence (ARO)
C.
SLE = Annualized Loss Expectancy (ALE) * Annualized Rate of Occurrence (ARO)
D.
SLE = Annualized Loss Expectancy (ALE) * Exposure Factor (EF)
Explanation:
Single Loss Expectancy is a term related to Risk Management and Risk Assessment. It
can be defined as the monetary value expected from
the occurrence of a risk on an asset. It is mathematically expressed as follows:
Single Loss Expectancy (SLE) = Asset Value (AV) * Exposure Factor (EF)
where the Exposure Factor is represented in the impact of the risk over the asset, or percentage of
asset lost. As an example, if the Asset
Value is reduced two thirds, the exposure factor value is .66. If the asset is completely lost, the
Exposure Factor is 1.0. The result is a
monetary value in the same unit as the Single Loss Expectancy is expressed.
Answer options D, B, and C are incorrect. These are not valid formulas of SLE.