A product is low on stock but the suggested order quantity is zero

The suggestion covers your target period plus the supplier's lead time, then subtracts both what you have available and what is already on order. A zero suggestion means one of the following:

1. Incoming stock already covers it. This is the usual answer. Stock you have already ordered counts towards the requirement, so the app will not tell you to order it twice. Check the incoming quantity on the row.
2. The product has no sales rate, as described above.
3. Available plus incoming already exceeds the target window. Nothing further is needed until that window shortens.