A security team is performing a quantitative risk analysis for a server valued at $100,000. The exposure factor is 0.4 and the annual rate of occurrence is 2. What is the annualized loss expectancy (ALE)?
This is the correct Annualized Loss Expectancy (ALE), derived from accurately applying the quantitative risk analysis formula. First, the Single Loss Expectancy (SLE) is calculated as the Asset Value ($100,000) multiplied by the Exposure Factor (0.4), yielding $40,000. This SLE is then correctly multiplied by the Annualized Rate of Occurrence (2) to determine the total expected financial loss over a year, which is $80,000.
Why this answer
The ALE is calculated as SLE × ARO, where SLE = Asset Value × Exposure Factor. Here, SLE = $100,000 × 0.4 = $40,000, and ARO = 2, so ALE = $40,000 × 2 = $80,000. This represents the expected annual monetary loss from the risk event.
Exam trap
CISSP often tests the distinction between SLE and ALE, and candidates frequently stop at SLE ($40,000) or forget to apply the exposure factor when computing ALE.
How to eliminate wrong answers
Option A is wrong because $40,000 is the Single Loss Expectancy (SLE), not the annualized figure — it omits the ARO multiplier. Option B is wrong because $200,000 incorrectly multiplies the full asset value by the ARO without applying the exposure factor. Option C is wrong because $160,000 results from multiplying the asset value by 0.4 and then by 4 (or some other misapplied factor), not the correct ARO of 2.