General questions about FMI

What are the license and usage conditions for the FMI standard?

Access and use of the FMI standard is free of charge. However, vendors may charge for their tools to support the FMI standard, either by exporting FMUs or by importing FMUs.

To be clear: While the FMI standard is open and free, commercial implementations might not be.

How can I join the FMI Mailing Lists?

  • The “FMI-Info-Mailing list” is used for public announcements. You can find a registration link on our contact page.
  • The “FMI design” Mailing list is used by active developers of FMI (typically members of the FMI Advisory or Steering Committee). If you are interested please contact
  • The “FMI Steering” Mailing list is used by members of the FMI Steering Committee. To join you need to be a member of the FMI Steering Committee.

How is FMI related to Modelica?

  • Technically FMI is not related to Modelica, and can be seen as a complementary technology.
  • The intention of the FMI project is to be neutral with respect to tools, technologies (e.g. solvers, OS, files, systems…) and languages (including Modelica).
  • The FMI standard is developed as a Modelica Association Project within the Modelica Association, an organization focused on the “coordinated standardization and development of software technology and methods in the area of cyber physical- systems and systems engineering”, see the Modelica Association Bylaws and the History page

I'm a modeler and want to use FMI in my simulation tool

How can I get a first overview on FMI?

Please have a look at the literature page, especially on the overview talks/slides from the 8th, 9th and 10th Modelica Conference

  • FMI 1.0: “The Functional Mock-up Interface for Tool independent Exchange of Simulation Models” PDF
  • FMI 2.0: “Functional Mock-up Interface 2.0: The Standard for Tool independent Exchange of Simulation Models” PDF
  • FMI 2.0: Presentations about new features and applications ZIP

Does my simulation tool support FMI?

Please see the FMI tools page for a list of tools for that tool vendors have announced their support of FMI.

While the FMI project defines cross check rules, the tool vendors carry sole responsibility for their stated FMI support and the provided compatibility results.

Where can I get help when I have problems related to FMI in my simulation tool?

  • Typically an exporting and an importing tool are involved in FMI-based simulation. So if problems occur and if it is not obvious which tool causes the problem, you should communicate the problem to the support team of both involved tools
  • As a general discussion forum about FMI, you may use the FMI forum on Stack Overflow

Is there a tool vendor independent way to access model information during simulation?

ASAM XIL-MA is a standardized API that allows the access of model parameters, stimulations and simulation results and to control simulation experiments as well. Please see the related ASAM XIL-MA section.

I'm a developer and want to support FMI with my tool

What and in which order should I read/do to get started with FMI technology?

That depends mostly on your background knowledge. We assume here you already have fundamental knowledge of simulation technology (ODE vs. DAE, zero-crossing, state/time events, derivatives etc.):

Does FMI 2.0 support Partial Differential Equations (PDEs)?

There are two kinds of FMI variants: Model Exchange and Co-Simulation.

Model-Exchange FMUs encode ODEs. PDE-support is not planned yet, but the demand for it is increasing.

The second kind, Co-Simulation FMUs, can contain any kind of simulation component because it does not expose states. So as long as you want to simply encapsulate PDEs, this could be done.

But explicitly exposing a PDE to a solver using FMUs is currently not supported.

I added my test FMUs/Cross-Check results but the tools page does not show "green". Why?

The Cross-Check Rules list a number of conditions before turning an entry “green”. In short:

  • Exporting tools must provide at least 3 FMUs and at least one importer must report successful import.
  • Importing tools must report (and prove) successful import of at least 3 FMUs of at least 3 exporting tools.

Please refer to the complete set of rules and notes.

Why are the badge-numbers of the platform-drop-down not adding up to the badge-number in the overview?

The platform-drop-down list contains only platforms the tool has passed the Cross-Check Rules. But the overview lists all FMUs or Cross-Check Results submitted.