1. A computer-implemented method to estimate the time to implement a regression test, the method comprising: storing a productivity table in a host computer system, the productivity table indicating the time expected to perform a plurality of automation script types at a plurality of complexity levels; receiving, at the host computer system, a list of test flows to be used in conducting a regression test; receiving, at the host computer system, a selection of a complexity level for each of the listed test flows, the complexity level selected based upon: the available resources of a computer system on which the regression test will be performed; the environment in which the regression test will be performed; statistical data describing scripts used in the test flow; the types of scripts used in the test flow; test definition documentation; and the technical knowledge of personnel associated with implementing the test flow; based upon the complexity level selected for each flow, the type of script used in the test flow, and the productivity table, determining the expected time to implement each of the test flows; based upon the expected implementation times for the plurality of test flows, determining the total expected time to implement the regression test; and storing, in the host computer system, the total expected time to implement the regression test.