Functional Mock-up Interface

The Functional Mock-up Interface (or FMI) defines a standardized interface to be used in computer simulations to develop complex cyber-physical systems.

The vision of FMI is to support this approach: if the real product is to be assembled from a wide range of parts interacting in complex ways, each controlled by a complex set of physical laws, then it should be possible to create a virtual product that can be assembled from a set of models that each represent a combination of parts, each a model of the physical laws as well as a model of the control systems (using electronics, hydraulics, and digital software) assembled digitally. The FMI standard thus provides the means for model based development of systems and is used for example for designing functions that are driven by electronic devices inside vehicles (e.g. ESP controllers, active safety systems, combustion controllers). Activities from systems modelling, simulation, validation and test can be covered with the FMI based approach.

To create the FMI standard, a large number of software companies and research centers have worked in a cooperation project established through a European consortium that has been conducted by Dassault Systèmes under the name of MODELISAR. The MODELISAR project started in 2008 to define the FMI specifications, deliver technology studies, prove the FMI concepts through use cases elaborated by the consortium partners and enable tool vendors to build advanced prototypes or in some cases even products. The development of the FMI specifications was coordinated by Daimler AG. After the end of the MODELISAR project in 2011, FMI is managed and developed as a Modelica Association Project (MAP).

The four required FMI aspects of creating models capable of being assembled have been covered in Modelisar project:

• FMI for model exchange,
• FMI for co-simulation,
• FMI for applications,
• FMI for PLM (integration of models and related data in product life-cycle management).

In practice, the FMI implementation by a software modelling tool enables the creation of a simulation model that can be interconnected or the creation of a software library called FMU (Functional Mock-up Unit).^[2]