Software solutions in complex environments, such as railway control systems or power plants, are assemblies of heterogeneous components, which are very large and complex systems themselves. Interplay of these systems requires a thorough design of a systemof-systems (SoS) encompassing the required interactions between the involved systems. One of the challenges lies in reconciliation of the domain data structures and runtime constraints to ensure consistency of the SoS behavior. In this paper, we present a generative approach that enables reconciliation of a common platform based on reusable domain models of the involved systems. This is comparable to a product line configuration problem where we generate a common platform model for all involved systems. We discuss the specific requirements for model composition in a SoS context and address them in our approach. In particular, our approach addresses the operational and managerial independence of the individual systems and offers appropriate modeling constructs. We report on our experiences of applying the approach in several real world projects and share the lessons learned.