1 INTRODUCTION
Cyber-physical systems (CPSs) are a vital part of modern society, with applications ranging from nuclear power plants and airplanes to cars and other complex systems. These systems usually consist of both cyber components (like controllers) and physical components, and their modeling and simulation often require multiple paradigms, including continuous-time, modal models, and discrete events. However, the wide variety of tools and formalisms used by different specialized companies to develop these systems can make it challenging to achieve interoperability (Gomes et al. 2019, Kubler and Schiehlen 2000). To address this challenge, the Functional Mockup Interface (FMI) Standard was developed to enable the exchange and co-operative simulation of black-box models (Blockwitz et al. 2012) using a vendor-independent interface. The black-box models are called Functional Mockup Units (FMUs) and describe the behaviour of a continuous subsystem as a discrete trace. An FMU can be composed with other models using input and output variables to form a larger system. Version 2.0 of the standard has been widely adopted, with more than 170 tools supporting it (FMI 2014), which has placed a growing demand on the standard to support simulation of real-time and reactive systems.