A comparison of the calculated performance factors with optimum and typical failure mode performance factors identifies {HEAD ~ performance problems} in {TAIL ~ the system} under test 
in
A comparison of the calculated performance factors with optimum and typical failure mode performance factors identifies { HEAD ~ performance problems } in { TAIL ~ the system } under test
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH