Deb
I suspect you have a few )'s in the wrong spot
Does this work ?
=IF(AND(B4="F",C4="B",A4="PLATE",(D4-E4)>=0),0,IF(AND(B4="F",C4="0",A4="PLATE",(D4-E4)>=0),(D4-E4),IF(AND(B4="0",C4="0",A4="PLATE",(D4-E4)>=0),(D4-E4),IF(AND(B4="F",C4="0",A4="CN",(D4-E4)>=0),(D4-E4),IF(AND(B4=0,C4=0,A4="CN",(D4-E4)>=0),(D4-E4),0)))))
If not can you explain the logic ?