Parametric estimating involves:

A. Defining cost or duration parameters of the project life cycleDefining cost or duration parameters of the project life cycle B. Calculating individual cost and duration estimates for each work package and integrating them to obtain the total cost or duration of the project.

C. * Using a statistical relationship between historical data and other variables to calculate an estimate for activity parameters, such as cost, budget, and duration.

D. Using the actual cost or duration of a previous similar project to estimate the cost or duration of the current project.