Hello all,
 
I am constructing part files and then inserting them into an assembly file. It was my understanding that if you modify a part in an assembly, the changes would be carried out throughout the project. When doing so, the drawings are updated with  say a new extrusion made in the assembly but the part file remains unchanged. Just wondered if anyone knows what I'm missing.
 
Thanks
 

Yes!
Parts only change if they are adaptive to one another. Meaning if you are in fact making part files, THEN inserting them into an assembly, said part will not adapt to anything. You need to create a component in place, while in the assembly.
For example, open up a new .iam. Insert part A. Now, click on 'create component'. Save the file where you need and name it. We will call it part B. You will select a surface of part A to mate part B to. Sketch enviroment will open. Click 'project surfaces'. Draw what you need to. Now, click 'extrude'. Hit return. Bang. New part B that is now adaptive to part A.

I don't know how and why, but when I modify part from assembly environment and then want to save to assembly it always provides me a list of parts of assembly and correctly marks those that have been changed.  I can even uncheck particular part to not save the changes in the original part file. Maybe I have Adaptive property defaultly set to true for each new part but I can't figure it now because that stress analysis with convergence is taking ages :-(

Yeah that list is standard behaviour. I get the same thing. Idea is that you can save only select parts while not saving others. Comes in handy some times.