IF(AND([Phase]@row = "COMPLETED”, OR Hand-off]@row = "N/A", [Hand-off]@row = 0),0,1)
So for Phase set to completed and where Hand-off is N/A or 0 or blank .. need to set 0, or else 1.
Or For Phase set to completed, where Hand-off is 1 - put 1.. for everything else put 0 ..