I. Introduction
The modular simulation of complex systems is recognizable since about four decades. The first approaches dealt with the reduction of simulation time in circuit design [3]. Nowadays, a decomposition of complex systems into manageable smaller subsystems is the classical approach to handle complex cyber-physical systems. Subsystems are developed/designed by teams of engineers in domain-specific (simulation) tools [3], [4]. During later development stages more and more practical realization aspects have to be obeyed and real hardware components may enter the design process. A holistic analysis of the whole system is still required to meet overall system design goals. Therefore, hardware components are often involved in form of real-time systems by the well-established hardware-in-the-loop (HIL) concept. The integration of the sub-models is typically performed by the use of existing model-export and -import functionality. To the end, a single system is simulated or compiled for the use on a HIL test system for analysis purposes. But depending on the used simulation tools and application (HIL) a holistic analysis approach may not be applicable in general [2]. Simulation tools and HIL systems are not equipped with the required features. As a consequence, a coupling of the distributed subsystems is necessary to analyze the system under consideration. This methodology is very similar to the classical co-simulation approach. Different subsystems are solved/evaluated for specific time instants and then synchronized.