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