Majorly three things has to be remember before using the item replacement.
Mandatory things:
1. The items which we are expecting for replacement those items should belongs to same category.
2. For A, b we have to create BPA
3. The Delivery date of PO either current date/ future date.
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1. Custom role creation
2. Creation of items
3. Creation of BPA
4. Creation of PO (PO does not have any receipts being created)