1. A computer-implemented method of determining estimation variance associated with project planning, comprising: obtaining information associated with a project, said project comprising a plurality of tasks; determining, by a processor, initial estimates and estimate variances of the plurality of tasks from the information; obtaining actual measurements associated with a selected task from the plurality of tasks after said selected task is executed; computing a difference between an initial estimate associated with the selected task and the actual measurements as the project progresses; revising, using the computed difference and the estimate variances, the initial estimates associated with remaining one or more tasks in the project, wherein the revising is further based on a design document created based on executing the selected task of the project; and determining estimate variances of said remaining one or more tasks based on the revised estimates, wherein the estimate variances include a variance of a statistical estimate computed as an average deviation of the statistical estimate from its estimated mean, said estimate variances including a measure of uncertainty in associated estimates, the method further comprising monitoring differences between previous estimations and ongoing actual values at different stages of a project life cycle as the project progresses.