I'm currently working with solidworks 2017 sp2. I noticed a problem with the use of sub assembly and sheet metal part.
I build a frame part where i put all general sketches, and i put this part in the general assembly and in every sub assembly. So i have my general assembly GA, for example, my frame part FP with all sketches, and a sub assembly SA.
FP will be within GA and SA, identically.
Now i create a sheet metal part within SA and i link its lenght of extrusion to the sketch of FP. I create two configuration of GA to have two measure in the sketch, in order to modify the lenght of sheet metal part with the configuration change.
Problem: changing the configuration in GA, FP change the measure, but i do not see any change in sheet metal part until i open the SA, only then the sheet metal part modify its lenght accordingly the FP.