Within this study, an analysis of the global standard panorama for wave energy converters (WECs) is presented, in order to develop design methodologies as close as possible to the state-of-the-art. In particular, an analysis of such international standards panorama exhibits a lack of information and detail regarding WEC system design, and the specific simulations procedures that shall be followed accordingly. In the light of this, this study proposes a standardised design process that can be followed to define the design loads which characterise a structural analysis, which are obtained by high-fidelity models. The device assessment in extreme states is analysed on intact and damaged conditions, where the use of a computational fluid dynamics (CFD) software is proposed to encompass any non-linear behaviour related to extreme events. Furthermore, this article also describes a fatigue assessment based on linear system theory, with the inclusion of linearised significant terms, such as, e.g. mooring influence on device dynamics.