A number of runs of completed insulating glass components in {HEAD ~ queue} to be assembled into {TAIL ~ insulating glass units} at the assembly station is monitored to identify a low queue condition of a given type of insulating glass component 
to be assembled into
A number of runs of completed insulating glass components in { HEAD ~ queue } to be assembled into { TAIL ~ insulating glass units } at the assembly station is monitored to identify a low queue condition of a given type of insulating glass component
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH