1. A computer-implemented method for ranking and optimizing automated test scripts, the method comprising: executing, on one or more computer systems, a plurality of test scripts, wherein the test scripts are members of a collection; recording, at a server computer, a test result and execution data in a repository for each of the plurality of test scripts executed; calculating, by the server computer, a score for each of the plurality of test scripts by multiplying a number of executions of the test script within a first period of time by a sum of a plurality of terms comprising a ratio of the number of executions of the test script resulting in a test result of failure not due to product bug to the number of executions of the test script within the first period of time, a ratio of the number of executions of the test script resulting in the test result of failure not due to product bug to the number of executions of the test script within a second period of time, and the number of executions of the test script resulting in a test result of failure due to product bug or failure not due to product bug within the first period of time based upon the test results and execution data recorded in the repository for the test script; ranking, by the server computer, the plurality of test scripts according to the score calculated for each; determining the members of the collection based upon the rank of each of the plurality of test scripts; and repeating the method over one or more iterations of testing.