Hi @VsoMDjewP 

Alternate part(s) connected to a specific purchase part and to connect new alternate parts to a purchase part. Alternate parts are parts that are interchangeable with the purchase part. 
Note: Only existing purchase parts at the same site can be entered.

In order to add alternative parts you can tick the “Alternative Parts Exist” check box in Supplier for Purchase part window.

If this check box is selected, it indicates that one or several alternate parts connected to the same supplier as the primary part exists at this site.
The alternate parts can be viewed and changed in the part catalog record for the primary part or in the Alternate Purchase Part Base Data window in IFS/Purchasing.
Note: All the alternate parts for a primary part are displayed even if no supplier has been defined for that relationship. 
To view the on hand quantity of the alternate parts, open the Inventory Part window and click the Alternate Parts tab.

Best Regards,
Tharaka.

Thanks for your reply. I will try this

@Tharaka Senevirathne  Dear Tharaka, I followed the steps you have mentioned.

1. I have added the alternate part in master part
2. I have added Purchase Alternate Basic Data 
3.  From Supplier for Purchase Part window if i right click and select “ Alternate Purchase Part” it shows the newly added parts

Problem is in the supplier for purchase part “Alternate Purchase Part” Tick is not updating and In PO window Change Alternate part RMB option is not activating 

Is there anything i am missing. Or is there any bug related to this in App10 UPD8

Hi @VsoMDjewP 

I am sorry I forgot to mention that you need to create a Supplier for purchase part record for that alternative part as well. In there you have to put the same supplier as in your Master Part. Then only you can tick that check box. 

Best Regards,
Tharaka.