After I read your message, I decided to let you know my experience with tolerance stackup. You are right on talking about the engineering culture and practice. However, I sadly say that tolerance analysis is not a solid engineering/science yet. Take a look at visVSA manual or training course books, there are all the detailed steps how to build a model and get results. THERE ARE NO THEORETICAL BACKGROUND mentioned. If you want to compare VSA with FEA, you can check all major FEA software manuals and you will notice the theoretical manuals there. I don't understand why visVSA does not provide its theory. You can image if I just follow you without understanding what the software is doing behind, I will not and can not go far. In my practice with visVSA, one of difficulties is the judgement of the results. How do I know I got issues in my models. I prefer thinking the issues with my models, instead thinking the bugs in the software. What will happen if we do have a bug !
in the software? How do I know? Yes, technical support there. How much time is needed. In industry, how many chances we have to report to management about the "trooubled" results?