How to get BOM compoents at the lowest level using BOM tables?

Question

I am doing a report based on CK13N wherein i hav material and plant as the selection parameters and based on that i get the product costing of the entire BOM.
I pass material to MAST.get the BOM num and usage
Pass it to STAS and get STLKN (ITEM NODE NUMBER)
After that i pass STLKN and STLNR(BOM number) to STPO to get the BOM subitems based on UPSKZ(Sub items indicator). But that fails because UPSKZ is nt set for all the assemblies.
So hw do i get the BOM components at the lowest level USING these TABLES

Answer 1

Ashwin
1) As Taj Said, Sub item is not actually a item or component.
2) The sub item number what we are viewing the sub item sceen will be 001,002 like ,it not mean any item
3) For Example a car has 4 wheels, so the item/component description is WHEEL
4) The BOM Quantity of wheel is 4
5) In BOM General item over view, you can select the wheel then click subitem
6) This will lead to sub item screen
7) There you can see subitem 001,002,003 then installation point,subitem text,qty etc
8) Against installation point you can decalre Front Left,Front Right,Rear Left,Rear Left
9) Against sub item text,qty you can declare Front Left wheel-1,Front Right wheel-1, Rear Left wheel-1, Rear Right wheel-1 no
9) This does not mean there are addition Sub items for wheel (ie) additional BOM component)
10) Just declaring the positions for fitting in the car to ease the Assembly Person for fixing the wheel
11) So if you get the cost for WHEEL as assigned in BOM item then ok, don't worry about sub item cost
Reward me if my answer is helpful
K.Prabakaran