Risk (glossary)

(1) Risk is a measure of the potential inability to achieve overall program objectives within defined cost, schedule, and technical constraints and has two components:

1. The probability (or likelihood) of failing to achieve a particular outcome and
2. The consequences (or impact) of failing to achieve that outcome.

A risk has a probability of occurrence that is greater than zero but less than one, a consequence of occurrence greater than zero, and a time-frame in the future. (Conrow 2008)

(2) In the domain of catastrophic risk analysis, such as for terrorist attacks or natural disasters, risk has three components:

1. Threat (the probability that a specific target is attacked in a specific way during a specified period)
2. Vulnerability (the probability that damage occurs given a threat), and
3. Consequence (the magnitude and type of damage resulting from an attack or disaster). (Willis et al. 2005)

Source

(1) Conrow,E. 2008. Risk Analysis for Space Systems. Paper presented at Space Systems Engineering and Risk Management Symposium, 27-29 February, 2008, Los Angeles, CA, USA.

(2) Willis, H. H., A. R. Morral, T. K. Kelly, and J. J. Medby. 2005. Estimating Terrorism Risk. Santa Monica, CA: The RAND Corporation, MG-388.

Discussion

Discussion as to why this is the "consensus" definition for the SEBoK.