The task of managing the operation of modern software system is challenging. It involves various stakeholders performing different tasks during the lifecycle of a software system. Furthermore, these activities and tasks are supported by various tools and technologies. The problem can be described with four challenges: functional heterogeneity, functional dependencies, technical heterogeneity and information management requirements. In this thesis we propose a modularization approach to define functional coherent units. These units are depicted using domain-specific metamodels. Since these functional units are not fully independent, the separation also requires an explicit integration of different functional domains to enable reuse from other units and address functional relationships. To address the technical heterogeneity, technology-specific information is separated from the functional descriptions of a software system. Technology- or tool-specific information is depicted by extensions to the functional models. Furthermore, this information can also be used to transform the models to technology-specific artifacts. Finally, the separation along functional and technical dimensions also requires additional methods for integration of concrete model instances motivated my operational aspects like the execution of models and concurrent modification by different stakeholders. For the concepts within this thesis a prototype based on the Eclipse Modeling Framework was developed. This prototype was used to model an exemplary operational lifecycle of software systems. Furthermore, a small user study was conducted to evaluate the applicability and acceptance of the proposed concepts.