1. A method for incorporating fail data from multiple applications of test patterns under varying environmental test conditions when performing diagnostic simulation on a device under test (DUT), the method comprising the steps of: a) applying said test patterns to said DUT under a plurality of said environmental conditions and collecting fail data resulting thereof; b) running diagnostic simulations under said plurality of environmental conditions; c) analyzing fault callouts from said running diagnostic simulations; and d) performing a physical failure analysis to the selective one of the said fault callouts.