When developing safety-related software or systems you need two things: argument and evidence. The goal structuring notation (GSN) is widely accepted to bring these two things together.
Actually, there also was www.goalstructuringnotation.info providing a complete specification of GSN but it currently seems to be broken.
I had to provide some arguments and evidence for a very special use-case recently to a customer. So wrote a litte script to easily create and modify my argumentation.
This is an example result:
I put my little script on github. It takes the arguments in a YAML file as input and outputs a DOT file that can be rendered using Graphviz.