Thus, the invention is best suited to robot welding in {TAIL ~ order} to improve {HEAD ~ productivity} 
Thus , the invention is best suited to robot welding in { TAIL ~ order } to improve { HEAD ~ productivity }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH HEAD HEAD HEAD HEAD HEAD