This paper presents the further development, implementation and evaluation of a computer-aided engineering (CAE) method for tool-independent simulation model coupling with a function-based modular framework for entire-system simulations. For that purpose, the preliminary findings regarding the development process of the function-based modular framework are presented. Emanating from that, a hierarchical structure for consistent data distribution and deposition for separating the system to be simulated is introduced. Therein the boundaries of the subsystems are defined, to avoid overlapping and ensuring a consistent ratio of the subsystems. Thus, the exchangeability and the reuse of simulation models are supported. Additionally, a scheme for signal names of the subsystems interfaces is described to allow general interoperability between the subsystems within the function-based modular framework. To prove the functionality and reliability of this CAE method based on a comparable granularity of encapsulated simulation models and without the need to redefine its standardized interfaces in the succeeding building and simulation process, a model of an electric car was implemented by means of the function-based modular framework. Based on this, an exemplary simulation result of the entire-system simulation is presented.