Parts Interchangeabilities - Supercession - Sales ATP

Hi All,

We are using Parts Interchangeability function with PIC01,..

Part A is replaced with Part B., following steps are maintained

1- Supercession chain

2- MRP Views, strategy group for Material master and all relevant views

But in Sales Order, the part is not getting replaced. As per below link from SAP, in the order,  replacement should automatically happen during ATP

http://help.sap.com/saphelp_erp60_sp/helpdata/en/1d/9caa384769ac0ee10000009b38f842/content.htm?frameset=/en/59/712938dd60fe64e10000009b38f842/frameset.htm

Any idea what could be missing?

Thanks

Regards,

Aby