A method of determining the feasibility of a proposed structure analysis process is disclosed. The process involved the electron beam excitation of x-rays from a multi-layered structure. The method comprises generating predicted x-ray data represents the x-ray excitation response of the multi-layered structure according to one or more sets of process conditions. The x-ray data are generated using structure data defining the structure and composition of the layers. The effects upon the x-ray data of changes to the structure data are then analyzed in accordance with one or more predetermined feasibility criteria, so as to determine the feasibility of performing the proposed structure analysis process upon the multi-layered structure.