Frequencyconsequence

Frequencyconsequence is a framework used in risk assessment to evaluate potential hazards by analyzing two dimensions: how often a given event occurs (frequency) and how severe the impact would be if it does occur (consequence). The term is not tied to a single formal standard but describes a common approach in safety engineering and risk management. In practice, risk is often quantified as a function of these two factors, with many organizations using a simple risk score obtained by multiplying estimated frequency by estimated consequence, though other scoring schemes are also used.

The frequency dimension is typically expressed as a probability per time unit or per operation, derived from historical data, service life, or expert judgment. The consequence dimension is defined by impact metrics such as injury or fatality risk, environmental harm, financial loss, production downtime, or reputational damage. The combination allows ranking of risks and prioritization of mitigations.

Applications span industries including chemical processing, aviation, nuclear, energy infrastructure, information technology and cybersecurity, and project risk management. For example, a rare catastrophic release has low frequency but high consequence, while a frequent minor incident has high frequency but low consequence. Both can drive different mitigation strategies.

Limitations include data quality, correlations between frequency and consequence, non-linear effects, and the challenge of modeling extreme, low-probability events. Frequencyconsequence remains a practical heuristic for risk communication and resource allocation, complementing qualitative assessments with quantitative ranking.