Resolved I just changed the purchase.py as follows:

    +if product.partner_ref:
    -            #name += '\n' + product.description_purchase
    +            name=product.partner_ref
            res['value'].update({'name': name})
            # - set a domain on product_uom

When you create a product, add supplier. In supplier you can specify supplier specify product details and supplier specify product reference

Hope this helps

As a newbie I need to ask where the file is located? Also, it would be helpful to know in what section of the file to insert the change. Is there a negative impact of the change?

After changing purchase.py as given above supplier reference could be seen in PO when we add an order from Quotations or Purchase Orders. However, description is equal to internal reference and name when we create an order from Purchase Requisitions. Is there any way to add supplier reference to orders when we create orders from Purchase Requisitions.