Hmmm - I worked with ProE ages ago Wildfire 1 or 2 - but I remember a nifty feature that would let you show your model in the maximum, nominal, or minimum material condition (i.e. you could set parts in an assembly to display at their largest, smallest, or nominal dimensions). It would let you see at a glance the tolerance stack up. I'm not sure if this feature is still in Creo, but I'd imagine it is. In order to have it work, you'd have to apply your tolerances to the actual dimensions in sketches and features (i.e. not reference dimensions in a drawing) - the dimensions that show up when you 'show dimensions'.
I don't recall having a feature like that in ProE (Wildfire). It would require for the tolerances to be built into the model and assembly constraints flexible based on tolerances. -Jason
Paul is correct, wf had the ability to set models to their upper/nom/lower limits. This pulls through to an assy of those parts without flexible dimensions. Creole has advanced this functionality, hopefully in the way of aligning the differently limited parts. I haven't played with these functions in Creo yet! hope that helps!
There was a software called Sigmetrics and PTC teamed up with them and now have this function embedded in the models. When you go to analysis you will see an option for this. It will allow you to specify CPK requirements and build your conditional loops based on the part features and assembly fit and function. WF5 now has the ability to fill gaps as well so you don't need to apply annotation features to fill the gaps and or spaces between part interfaces. The functionality works quite well at identifying design sensitive issues in you assembly. It will allow you to get to a specific condition 6 sigma etc. I really like it for create tolerance balance in my designs and think it also gives you visible means to identify true critical dimensions verses perceived critical dimensions. As far as training its out there but I found PTC has some good foundation stuff but you really need to go build the loops yourself and see how easy it is to manipulate them. The part that is tough is getting the loop clearly defined as until this happens it will not process. Just so you understand its not about adjusting parts as it is to identify critical fit and function issues.