Establishing a uniform definition for likelihood and impact best enables an enterprise to reduce variance in the assessment of risk. This means that the enterprise can have a consistent and comparable way of measuring and evaluating the probability and consequence of potential events that may affect its objectives, operations, and performance. A uniform definition of likelihood and impact can help to avoid confusion, ambiguity, or bias in the risk assessment process, as well as to improve the quality and reliability of the risk data and analysis.

Some references for establishing a uniform definition for likelihood and impact are:

Risk Assessment: Likelihood & Impact, which provides a guide on how to conduct a risk assessment using a clear formula that involves likelihood and impact1.

Risk = Likelihood x Impact, which explains how to calculate the total amount of risk exposure using likelihood and impact2.

How Analysis, Likelihood, and Impact Models Work Together, which describes how to use different models to express the chance, consequence, and score of a risk3.