Part of a factory (8,4)
I believe the answer is:
assembly line
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">part of a factory</span>' is the definition.<br/ ><span class="explanation-format__explanation">('assembly line' is part of 'factory')</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for assembly line that I've seen before include "Series of machines in factory" , "Manufacturing set-up" , "Factory fabrication process" , "Eg, car plant set-up" , "Mechanical system for mass production" .)