As digitization progresses, the integration of information and communication technologies in technical systems is constantly increasing. Fascinating value potentials are emerging (e.g. autonomous driving), but also challenges in the system development. The constantly increasing product complexity and degree of networking require a systemic development, which is fulfilled by established approaches of Model-Based Systems Engineering (MBSE). To ensure the reliability of tomorrow's systems, an integrative and early consideration of security and safety is additionally required. In order to show the possibility and consequences of failures and attacks, the paper develops a modeling language that links established and partly isolated security and safety approaches within a consistent metamodel. The developer is enabled to synthesize system architectures transparently on an interdisciplinary level and to analyze attack and failure propagation integratively. The approach uncovers synergetic and especially contrasting goals and effects of architectural designs in terms of safety and security in order to make adequate architectural decisions based on trade-off analyses.