Risk Likelihood and Impact

Risk Likelihood and Impact refers to the two core dimensions used to assess an identified risk, evaluating separately how probable it is that the risk will actually occur and how significant the consequences would be if it did, combining these two assessments to determine how much attention and resource investment a given risk genuinely warrants relative to others. This paired assessment sits directly after risk identification and classification within Agile Risk and Uncertainty Management, providing the analytical basis on which prioritization and response planning are built.

Understanding Likelihood

What Likelihood Represents

Likelihood is an estimate of how probable it is that a specific identified risk will actually materialize within the relevant timeframe of the project, distinct from the separate question of how bad the outcome would be if it did occur.

Sources of Evidence for Estimating Likelihood

Likelihood estimates draw on available evidence such as historical frequency of similar risks in past projects, current indicators already observed, and the informed judgment of people with relevant experience or expertise, since precise numerical probability is rarely available for most project risks.

Expressing Likelihood in Practice

Likelihood is often expressed using a simple ordinal scale, such as low, medium, or high, rather than a precise numerical probability, since project risks typically do not support the kind of statistical precision available in more controlled or repeatable settings.

Understanding Impact

What Impact Represents

Impact is an estimate of the severity of consequence that would result if the risk actually occurred, considered independently of how likely that occurrence is, and typically evaluated across relevant dimensions such as schedule, cost, quality, or scope.

Considering Multiple Dimensions of Impact

Because a single risk can affect several aspects of a project simultaneously, impact assessment often considers multiple dimensions together, recognizing that a risk with modest cost impact but severe schedule impact should not be evaluated on cost alone.

Expressing Impact in Practice

Like likelihood, impact is commonly expressed on a simple ordinal scale, allowing risks with very different specific consequences to be compared on a consistent basis without requiring precise, and often unavailable, quantification of exact loss.

Combining Likelihood and Impact

The Purpose of Combination

Assessing likelihood and impact together, rather than considering either alone, provides a more complete picture of a risk's true significance, since a highly likely but low-impact risk and a rare but severe risk both warrant attention, though for different reasons and often through different types of response.

Risk Matrices as a Common Tool

A common way to visualize combined assessment plots each risk on a grid with likelihood along one axis and impact along the other, allowing risks to be compared at a glance and grouped into overall priority levels based on where they fall on the grid.

Resulting Priority Levels

Risks assessed as both highly likely and highly impactful typically warrant the most immediate and thorough response, while risks low on both dimensions may require only periodic monitoring, with risks high on only one dimension falling somewhere between these extremes depending on the specific context.

Practical Considerations in Assessment

Avoiding False Precision

Because project risk assessment relies heavily on judgment rather than hard data, using detailed numerical scores can create a misleading impression of precision; many Agile teams favor simpler qualitative scales that acknowledge the inherent uncertainty in the assessment itself.

Reassessing as Conditions Change

Likelihood and impact are not fixed properties of a risk but can shift as a project progresses, new information emerges, or mitigating actions are taken, requiring assessments to be revisited rather than treated as permanent once initially recorded.

Involving Multiple Perspectives

Because different people may reasonably estimate likelihood or impact differently based on their own experience and vantage point, involving multiple contributors in the assessment process tends to produce more balanced and reliable estimates than relying on a single individual's judgment.

Consequences of Poor Assessment

Misallocated Attention and Resources

If likelihood or impact is significantly misjudged, effort may be directed toward relatively minor risks while more significant threats receive insufficient attention, undermining the overall effectiveness of the team's risk management effort.

False Confidence From Overly Optimistic Estimates

Consistently underestimating either likelihood or impact, whether due to optimism bias or incomplete information, can leave a team unprepared for risks that were assessed as less significant than they actually turned out to be.

Visual Representation

Risks plotted in the upper-right region, combining high likelihood with high impact, warrant the greatest priority. This combined assessment can be expressed as:

Risk Likelihood and Impact provides the two essential inputs to this function, forming the analytical basis for how attention is allocated across all identified risks in an Agile project.