This document discusses complex systems of systems (SoS) and challenges in modeling and analyzing them. It provides an overview of Kim Larsen's activities related to SoS, including research projects on safety critical systems, smart grids, intelligent buildings, and more. It also outlines key features of SoS like their distributed, collaborative, large-scale nature and challenges like adaptivity, openness, and meeting quantitative constraints. Directions for addressing issues like dynamic behavior, game theory, correctness and optimization are mentioned.