person Author: Process Fellows
When estimating effort, cost, or duration in a project, it's essential to account for uncertainty and potential risks. Here are common approaches used to incorporate risks into estimation:

1. Three-Point Estimation: Uses optimistic, most likely, and pessimistic estimates, helps quantify uncertainty and calculate expected values.
2. Expert Judgment (e.g. as part of Delphi method): Involves consulting experienced team members or stakeholders. Helps identify hidden risks and validate assumptions.
3. Risk-Based Estimation: Identify specific risks and assess their potential impact on estimates. Adjust estimates based on probability and severity, considering as well preventive and corrective actions. This is typically supported by a risk register and impact analysis.
4. Historical Data and Lessons Learned: Use data from previous similar projects to anticipate common risks. Helps refine estimates and improve accuracy.