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