A suite of modelling tools is being created for the European Integrated Project "Emerging Nano-Patterning Methods". The idea of an optimal processing window for nano-imprints is presented, together with its limiting factors. Stemming from these factors, the need for a fully integrated multi-scale modelling is identified, where the overlap is on three levels: at the wafer scale for pressure and residual layer thickness distribution, at the cavity scale for fluid dynamics, and at the sub-nanometre scale for fluid-stamp interactions. The residual layer thickness is a critical parameter for embossing large areas, and accurate modelling at various scales is needed, in order to predict simultaneously cavity filling and thickness homogeneity at the wafer level. To do so, a finite element model is first introduced, where ANSYS is used to solve for the fluid flow in channels of infinite length. To check that the model accurately captures all the salient features of imprinting, two studies are carried-out. Firstly, it is shown that the model reproduces well the profile of the fluid front in a cavity for a range of viscosities. Secondly, the model is successfully compared to the experimental results of load-instrumented single cavity nano-imprint. Finally, a larger model is built by assembling the elementary channel feature defined above, and the velocity profiles in adjacent channels are analysed.