Ensuring {HEAD ~ alignment} of {TAIL ~ the data} in time for all the subsystems is problematic 
of
Ensuring { HEAD ~ alignment } of { TAIL ~ the data } in time for all the subsystems is problematic
OTH HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH