Just thought I would share this link to an open source software called NShape. I haven't fully grasped all the aspects of the software but it seems to fit in with AHMI very well. My initial goal with this was to create a dynamic wiring diagram that showed not only the circuit but the energized parts with colors as they changed. Even with my basic knowledge of VB, I was able to get the libraries and a basic project started. There is also a good tutorial for ambitious newbies like me to learn VB. Hope you enjoy.
http://nshape.codeplex.com/