In this paper, we present a framework for the simulation of electronic devices based on a multiscale and multiphysics approach. A formal description is provided that includes both multiscale and multiphysics problems and which can be linked to already established multiscale methods. We present a set of simulations of an AlGaN/GaN nanocolumn based on a multiscale coupling between atomistic descriptions and continuous media models, illustrating the application of such a multiscale approach to electronic device simulation.