When a part or assembly file to which you have linked changes, the program highlights the changed file in the browser.
When you right-click the highlighted file and select Update from the menu, the program updates the model as well as all generated drawings views.
If you have overridden parametric dimensions (for example, adding tolerance values to a parametric dimension), the program discards those overrides. None of the other dimensions are affected.
As with parametric dimensions, if you override any of the BOM columns derived from iProperties, they are overridden.