Functional Safety Suite

Functional Safety Suite 5.1

This is a tool for calculations in the field of functional safety. It is free of charge.

Model types:

New in version 5.1:

Bugfixes in version 5.1:


New in version 5:

Main characteristics and abilities:


Minimum System Requirements

Note: Functional Safety Suite 5.1 might not correctly run with Java Version 8 (also indicated as 1.8.x). If you cannot update to Java Version 11 (or 12), you can use Functional Safety Suite 4.0.2, see below. You can check the version by typing java -version on the command line.

To run Functional Safety Suite you'll need a JAVA(TM) virtual machine (JVM, also called JAVA Runtime Environment, JRE) on your computer.

Functional Safety Suite 5.1.0 has been verified to run on Microsoft Windows 7 with AdoptOpenJDK version 11.0.6 and on Microsoft Windows 10 with AdoptOpenJDK 12.0.1.

The installer will run on Microsoft Windows as well as on some Linux distributions (it has been reported to run on an Ubuntu Linux machine). It will guide you through the installation. Download the .jar file to any directory and double-click on the .jar file. If the Java Runtime Environment (JRE) is installed correctly, the installation will usually start. If nothing happens, open a command line, go to the directory where you've downloaded the installation file and type java -jar fusasu_5.1.0_installer.jar

If you're running Linux, you might need to change the 'executable' flag on the file //dist/FunctionalSafetySuite_5.1.0.jar. If short cuts were added to the menu, remove them and make new ones to the file stated above. Installing from the archive might be slightly faster for linux users, anyhow.

If you cannot start the installer from the command line, your Java Runtime Environment (JRE) is not installed correctly. In particular some OpenJDK distributions don't automatically set the JAVA_HOME system variable. In that case, you have to set the JAVA_HOME system variable manually, see Maybe you also need to adjust the PATH variable for the "bin" directory of the Java JRE installation, see

If for some other reason the installer doesn't work, please download the .zip file instead and extract it to some folder. A directory "FunctionalSafetySuite_5.1" will be created with some sub-directories. The only difference is, that no shortcuts will be created.

If you have problems installing Functional Safety Suite, please write an email to Please send the output of java -version (this command must work independent of the current directory) as well. Please also try java -jar dist\FunctionalSafetySuite_5.1.0.jar (after changing to the installation directory of Functional Safety Suite).

The installer will not change any system parameters or libraries. Therefore, for de-installation you simply need to delete the directory that has been created during installation.

Functional Safety Suite will create a file 'fusasuV4.prop' in the user's default directory. If you change from Functional Safety Suite version 4.x to 5.x, the old file will be reused.

Legal aspects

The complete license is part of the download (see file "license.txt"). The following is only a short excerpt.

Functional Safety Suite including the documentation is provided "as is" without any warranty to their performance, correctness or fitness for any particular purpose. The licensee assumes the entire risk as to the quality and performance of the software. In no event shall the author or anyone else who has been involved in the creation, development, production, or delivery of this Software be liable for any direct, incidental or consequential damages, such as, but not limited to, loss of anticipated profits, benefits, use, or data resulting from the use of this software, or arising out of any breach of warranty.

Functional Safety Suite Demo Edition

Differences between the Demo Edition and the full version:

To obtain a license for full functionality of Functional Safety Suite for free, please write to

Please state the name of your company or for which purpose you intend to use Functional Safety Suite. You'll receive the license within three days typcially, except when I'm in holidays or on a business trip.


The file 'fusasu_5.1.0_installer.jar' includes the program, the documentation (pdf and html) and some examples.

If the installer doesn't work for your system, please use the .zip file instead:

Please read the documentation first.

Upgrade from version 4.x to version 5.x

All projects created with version 4.x can be opened in version 5.x and vice versa. The main difference is, that if you want to calculate the unreliability, you'll have to select the "calculate unreliability" option in the evaluation properties for some models in version 5.x, because it might not be calculated in parallel to the unavailability or failure rate anymore. In addition, the range of some generic basic event values have been changed slightly, e.g. the value "0.0" might be ok in one version but not in the other. You'll at least be warned during evaluation in that case.


Event tree:
Screenshot event tree
Fault tree:
Screenshot fault tree
Reliability block diagram:
Screenshot reliability block diagram
Markov model:
Screenshot Markov model
Complex component:
Screenshot complex component model
Chart of complex component values:
Screenshot complex component chart

Old versions

Functional Safety Suite 5.0.0

This version is replaced by 5.1.0, see above. There is no use case for this version anymore.

Functional Safety Suite 4.0.2

This version is replaced by 5.1.0, see above. It is recommended to upgrade to version 5.x since version 4.x is no longer maintained. Version 4.0.2 should only be used if version 5.x is not running on your machine.

The file 'fusasu_4.0.2_installer.jar' includes the program, the documentation (pdf and html) and some examples.

If the installer doesn't work for your system, please use the .zip file instead:

Copyright 2020 by Thomas Brunnengräber, Munich, Germany