Hi all, I am writing a program for tolerance stackup analysis, and I wanted to know kind of problems designers face with respect to existing softwares currently. For example, I found out that using GD&T and monte carlo simulations, many ASME 14.5 rules cannot be incorporated. Also the major problems with these packages are that the results depend on the expertise of the user, not just the GD&T specifications. So what are other problems that need to be addressed. Thanks a lot!

There are already several good software packages for tolerance analysis that integrate directly with the CAD systems. Google 'tolerance analysis software'

Try QuickTol's QTA. It's an excel add on specifically developed to quickly produce Tolerance Analyses results. It's is capable of various analysis types such as Monte Carlo, Worst Case, and Sensitivity. It's simple. Just input the data, and let the tool do the work. QTA is intuitive. It is easy to know which dimensions goes where.