PDM check in - sub assembly update how does it work?

I having problems with my PDM check in and update.

Im not sure if it is working correctly or not.

If i open a top level assembly,  and then open a part that is within a sub assembly,  edit that part and then save it. then open the top level, rebuild it appears correct.

Now when i check in, what is the best/correct way to do it.

Currently, i check in from the top level Assembly drawing, (The part i changed has a Green arrow next to them) so on the check in screen i can add the drawing of them them to the Check in list)

Howeever, Unless i open the sub assembly it does not update. (only the Part and the top level update)

Is there no way i can check in the top level assembly it will update all references? or something, because within a large Assembly i can see there being problems/alot of time having to open all the assemblies that have parts that have changed (and remembering to do it). even trying to remember them. and then having to select there drawings in the check in box?

Im not sure if i have something set up wrong or my check in procedure is wrong.

or do i have to just make sure i open all the sub assemblies that have parts that have changed and save them?

SolidworksWorkgroup Pdm