Simulation results can be deemed usable, or not by ranking it against another in order to find out how a specific simulation run affected coverage results of another simulation run. The coverage results saved to an ACDB database can be ranked by using the ACDB rank command. This classifies the results based on contribution of tests to the total coverage score. Cost parameters like simulation time or CPU time may also be taken into consideration to focus on test runs which yield the greatest coverage value in the shortest amount of time. See “Ranking Test Results” in Active-HDL help.