Parametric Estimating is a statistical technique used in project management to estimate project costs or durations based on historical data and mathematical relationships. It involves identifying parameters that influence the project, such as size, complexity, or resource availability, and using these parameters to create estimates. This method is particularly useful when there is a wealth of historical data available. By applying formulas or algorithms, project managers can generate more accurate estimates than using simple averages or expert judgment alone. This approach helps in budgeting and scheduling, making it easier to plan and allocate resources effectively throughout the project lifecycle.