Use this in D7 of utilization sheet

=SUMPRODUCT(('[Sample Allocation.xlsx]Plotter'!$K$4:$Q$4>=INDEX('[Sample Allocation.xlsx]Plan'!$H$4:$H$9,MATCH($B7,'[Sample Allocation.xlsx]Plan'!$G$4:$G$9,0)))*('[Sample Allocation.xlsx]Plotter'!$K$4:$Q$4<=INDEX('[Sample Allocation.xlsx]Plan'!$I$4:$I$9,MATCH($B7,'[Sample Allocation.xlsx]Plan'!$G$4:$G$9,0)))*ISNA(MATCH('[Sample Allocation.xlsx]Plotter'!$K$4:$Q$4,'[Sample Allocation.xlsx]Plan'!$R$3:$R$4,0)))