Hi

To define dynamic ranges,

hit CTRL + F3,

Click on New > In the name box type LastRow and in the refers to box type the corresponding formula > OK.

repeat the steps for PasrtsNo, Qty and WIP_No.

Now put the formula in T3 and copied down,

=IFERROR(INDEX(WIP_No,MATCH(TRUE,INDEX(PartsNo&"|" &Qty=R3&"|"&S3,0,0),0)),"Not found")