1) Create a supplier logic (This is a code used to create the promotion):
          Control Panel ->System Admin -> Drop Down List Configuration
    Select 'Supplier Type' as the category, add the sort code, code, content etc.
    Click on 'Add Item' once done.

2) Edit the supplier logic to follow the promotion:
          Supplier -> Maintenance -> Edit Supplier
    Choose a supplier, change the 'Supplier Logic' according to what has been added in part 1.

3) Crete the promotion using pricing matrix (Apply to the supplier/s selected in part2)
          Inventory -> Maintenance -> Pricing Matrix -> Create
     Choose Entity type according to the sort code created in part1
     Give the item code (example: YMS-ITEM2) -> Get Pricing Scheme
     Make sure the category field follow the chosen item category fields (you can check the category from: Inventory->Item->Edit Item)
     Put in the relevant information: discount %, branch, date range etc.

4) To test the promotion:
           Trading-> Purchase -> Direct Receiving Stock
     Choose the supplier from part2(promotion apply to this supplier), Choose the item code from part3(promotion applied to this item). In the item detail page, you should be able to see the discount option in the drop down list.