beneath SysML engineers use Failure Mode and Effects Analysis, Fault Tree Analysis, Event Tree Analysis and Marcov Analysis.
In all these elements you start modelling and enhance the graphical part later with some management or engineering information (estimations and probability numbers).
Today there is some break: the requirements/model information is in some UML/SysML tool, then you rebuild this only for adding the numbers e.g. in some poor looking Fault Tree tool. ... please check for integrating this in your nice and very agile modelling tool.
In case you are interested please ask for informationen.