Risk

Risk is the possibility that something goes wrong. It is a measure of uncertainty about the effects, consequences, or implications of an activity or a decision, usually understood in a negative sense against some value that matters – money, health, or a system quality attribute such as availability or security.

The conventional way to quantify a risk is as the product of the likelihood that a problem occurs and the impact – usually a loss – if it does. This is why a rare but catastrophic event and a common but minor one can carry a comparable risk rating, even though they call for very different responses. Where the uncertain outcome could equally be a gain rather than a loss, the more accurate term is not risk but opportunity or chance. Risk assumes the downside framing.

In software systems, risk analysis is a routine part of threat modeling and architecture evaluation, where identified risks are weighed against a design’s trade-offs and sensitivity points, rather than treated as a single fixed number to be eliminated.