However, it is also recognized that {HEAD ~ the preassembly} of the top frame units may occur in {TAIL ~ the manufacturing/assembly facility} itself in response to a customer order 
occur in
However , it is also recognized that { HEAD ~ the preassembly } of the top frame units may occur in { TAIL ~ the manufacturing / assembly facility } itself in response to a customer order
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH