The consideration of the techno-economic feasibility of grid development goes hand in hand with securing the supply, the resilience of energy systems at all grid levels and seamless integration across all grid levels. In particular, the analysis of potential new vulnerabilities of the energy system due to digitalization (smart grids) and the investigation of the social impact of energy outages form an essential basis for optimized grid planning and management. As part of this research, complex optimization problems are examined at both the grid planning and operational management levels in order to identify sustainable and resilient energy system designs.