"Can I change Global Variable of part from Assembly instance"
I need drive global variable's of part form assembly global variable is it possible in solid works.
If yes please let me know how?
I think I know what you are trying to do... but, if I'm right about it, I wouldn't go that way.
Equations (and global variables) in parts often don't update automatically when you rebuild the top level assembly.
Probably, the best way to make an assembly to control the size of parts is to draw a "master sketch" at top level assembly (with just the critical dimensions/references, no need to get too detailed) and then make the sketches inside the parts to follow that sketch.
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