Traditional low-cost bulk materials are unable to fulfil the increasing requirements of actual technology and functional coatings – e.g. APS alumina coatings on aluminium substrates for tribological properties – are a suitable alternative. The development of new thermal sprayings is usually based in experimental procedures which involve long development times and high costs. Nowadays, numerical simulation allows the researcher a better understanding of thermal spray processes as well as reducing the time and cost for the optimization of processes, but it requires a deep insight into the physics of the phenomenon. The submodelling approach allows the researchers to work with a local model, a thin layer – just a few microns – on the metal substrate surface, and more realistic boundary conditions, which requires a little specialised knowledge. The current study involves the workflow to manage the modelling at piece scale, and the transfer and interpolation of boundary conditions in each scale. The coating is divided into several layers, which represent the successive splats deposited during the process, and the heat flow from the torch is modelled by radiation and convection. A code is implemented in order to generate the routine needed by the FEM software, in which the results are processed and interpolated for the subsequent submodel. Furthermore, the material plasticity is considered and several tests are performed in order to check the simulation results.