Strategy 60 don't reduce the Ind Req.

Dear Gurus

i need to implementation planning strategy 60 for my customer.

I have execute the following steps:

1) Create Material planning with strategy 60 with reduce period anche MRP dual = 3

2) Create 2 FG in which in the MRP3 i have inserted planning material and Plant.

3) Create a Bom for Material planning with component FG1 and FG2 .

4) Create Ind. Req (md61 ) for planning material.

Now when i created a new sales order for FG1 i would like that the PIR for planning material is reduced from the same quantity but the PIR quantity in material planning is always the same.

What i can check for to have the standard scenary (60)?

Thanks a lot

Daniele