In project planning and business analysis, impact analysis has two highly useful applications. The first is to discover what impact a given solution will have on the business. For example, if the project team faces a choice between several solutions, running an impact analysis against each solution will help identify the least disruptive choice.
The second primary application for an impact analysis is in assessing the impact of changes that occur during a project's lifecycle. Analyzing the impact of a change helps determine if the change is feasible and has business value.