This paper targets to show feasibility of a three-dimensional process simulation flow in the context of optimization of the device design and the underlying fabrication processes. The simulation is based on and refers to the development of the SOI-based 30 nm FinFET devices. The major goal of the simulation work is to implement a complete FinFET process flow into a commercially available 3D process simulation environment. Furthermore, all important three-dimensional geometrical features, such as corner roundings and 3D facets, have been introduced into the simulation set-up. After the successful demonstration of a functional 3D process simulation flow, detailed issues of process simulation methodology are assessed, such as the usage of different dopant diffusion models or the modelling of specific oxidation processes plus assessment of different annealing conditions. Finally, a comparison of the simulation results with electrical measurement data is performed which shows fairly good agreement.