The present invention relates to a method for finding design weakness and potential field failure of a PCB assembly which includes components, comprising the steps of: (a) creating a model of the PCB assembly by which natural frequencies and mode shapes of the PCB assembly can be determined; (b) performing a natural frequencies simulation for determining natural frequencies and mode shapes of the PCB assembly; and (c) analyzing said determined natural frequencies and mode shapes and identifying local dominant oscillations of components, components identified as having a local dominant oscillation in at least one of said determined mode shapes are identified as components having a relatively high potential of field failure.