The developments in EMC modelling permit to estimate the disturbances in different kinds of circuits and installations, to define a protection philosophy and to evaluate its efficiency. Using some examples of modelling, the paper discusses whether these possibilities are useful for the standardization in progress in the European Community. It is shown that essential progress has been made in the last years in modelling field-to-transmission line coupling, crosstalk, antennas, and shielded enclosures and that these models can be applied to define parameters and environments needed for standards