In german we call it sometimes "Endmontage", maybe translated by "final assembly". It includes not only the assembly, but also the needed calibrations and final tests.
But if the additional procedures take up much space, we declare them separately, like "Voralterung" ("preaging"), etc.

Kai

PS.: Isn't it funny, that a german tries to help a slovakian to find a proper english term? I hear the native speakers of the forum members dying of laughter...