Formal methods based on abstract models are becoming more and more important in the domain of complex computer networks. On the other hand, processes of design documentation transformation into the formal models are still bound to the skills and ingenuity of individual engineers. Moreover, the human factor involved in data transformation represents a major bottleneck due to the tendency of computer networks to be more and more complex. To address this problem, this work introduces a formal model based on the concept of multilayer networks for applying a system methodology to network analysis and an appropriate presentation format of architecture descriptions as a possible part of detailed design documentation that could allow automated generation of trusted formal multilayer models based on this documentation.