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