Formal Methods for Developing and Changing Engineering Systems

I was reading this post:

It made a lot of sense, but it was missing the critical part of how to plan. Planning should be done at the creation of a system (any system complex enough for both sides of the napkin) and for changes (which are guaranteed to occur). But are there formal methods to do so? Yes.

One time-tested formal method is Systems Engineering. (SE). This is used in projects like…