Probabilistic Risk Assessment


Probabilistic Risk Assessment

Type of quantitative risk assessment that considers possible combinations of occurrences with associated consequences, each with an associated probability or probability distribution.

Sample Usage: The engineers conducted a probabilistic risk assessment to determine the risk of an accident resulting from a series of compounding failures.


  1. Probabilistic risk assessments are typically performed on complex technological systems with tools such as fault and event trees and Monte Carlo simulations to evaluate security risks and/or accidental failures.
  2. For some types of risk, like those involving human volition, the probability of occurrence of an event may not be independent of the consequences and, in fact, may be a function of the consequences.

Source: DHS Risk Lexicon, U.S. Department of Homeland Security, 2010 Edition. September 2010 Regulatory Guidance