Imagine that I have an part that is a simple square steel plate with Lenght*Width*Thickness.
Then in one assembly i want to add one plate with 200*200*10 and another with 200*200*5. Is it possible to have the same part with diferent dimensions? or do i really need to create an iPart. I'm having problems with my drawing manager software when i make iparts and i assemblys.....
I probably wouldn't create an iPart for just two variations of a simple plate.
I'd probably just open the plate, do a "Save As", then edit the thickness and save the part.
You could also do this in the assembly by using the "Save and Replace Component" function.
If you were going to require many different thicknesses, then I would consider making it an iPart.