1) There would be multiple suppliers
2) Each supplier has their own stock. All suppliers might have same product but different quantities
3) Portal should be for Admin, Suppliers and Customers.
4) Admin creates suppliers, gives their respective logins to them and also updates their respective stock.
5) Buyers also get their login (All are internal buyers. No end customer involved in this portal). Buyer will login to place orders. Buyer wont be aware of different suppliers availability.
6) When buyer places orders, order should come to the backend after which admin will decide which order should go to which supplier.
7) Orders once assigned to suppliers, depending on the orders assigned quantity should be deducted from their respective accounts. Due to any reason if supplier chooses to cancel the order, stock should add back automatically to that supplier
8) Supplier once marks the order as shipped, he should be entering a tracking number and click submit. This tracking number should be visible to respective buyers.
9) Admin should be able to re-assign order, add comments, edit orders, download orders etc.
10) Suppliers after marking the orders as shipped, order should disappear from their account. Only admin should be able to see them. Respective buyers who placed the orders will be able to see their orders along with tracking id or status (Declined or Approved)
11) Contact me if more clarity is required.