Dear André,
Thanks a lot for your answer, and please to find my example :
On hand stock of item SS017P01 : 170 445 (nettable and not expired)

The supply forecast : with selection of activated formula

When performing the above sypply schedule, planned orders are :
Qty in plan is exactly the forecast one, no consideration of stock

and pegging section in the prod planned order is empty :

Appreciate your kind support, thanks in advance André.
Best regards.