Modelica (https://www.modelica.org https://www.modelica.org) is another useful option for MBSE that has more commercial front-ends than one can shake a stick at

Modelica (https://www.modelica.org https://www.modelica.org) is another useful option for MBSE that has more commercial front-ends than one can shake a stick at (e.g., CATIA and Wolfram SystemModeler), as well as free options. There's also a Systems Engineering version of Enterprise Architect (http://sparxsystems.com.au/products/ea/systems.html http://sparxsystems.com.au/products/ea/systems.html) that I think is great for the price.