Thanks for the clarification! This makes sense.

I do wonder who is liable if the software used to design a bridge outputs incorrect simulation results and the bridge collapses as a consequence. I suppose it's on the senior project engineer (or whoever ultimately signs off on the design) to verify the results somehow.

Edit: This article [0] talks about "trust" being placed in commercial CAD software by engineers and doesn't mention regulation/certification of the software itself, which seems to imply that there is none.

[0] https://www.simscale.com/blog/open-source-software-cae/