Sales order BOM

Dear Expert,

How to create Sales Order BOM.of following ?

We have process FERT Halb3 -halb2 -halb1 raw material.

Currently First we create Production order of Halb1 material used Raw Material

then create Production order of halb2 material used halb1

Halb3--halb2

Create Production order of FERT material used halb3.

in cs11 it looks like

FERT 1Ea

Halb3 1 EA

Halb2 1 EA

Halb1 1 EA

Raw 2 kg

Scrap 0.25kg-

i want to create Sales order BOM of above how to create?

Please guide me.

Thanks & Regards

Pert