On hand, committed, held, available
Each product (or variation) in a warehouse has four figures:
| Figure | Meaning |
|---|---|
| On hand | Units physically in the warehouse. The one you type. |
| Committed | Promised and not yet gone (used by Advanced Inventory). |
| Held | Set aside, for example damaged. |
| Available | On hand − committed − held. Only this can be sold. |
On most stores committed and held are 0, so available equals on hand. When an order is placed, units leave on hand straight away; cancelling puts them back.
Bins
Turn on bins in a warehouse's Settings tab (Use bins in this warehouse). Bins record where units sit, not how many: for example on hand 40 = A-01-02: 25 + B-03-01: 10 + Not in a bin: 5. Units leaving the warehouse are taken from loose stock first, then bins in code order.
Can stock go below zero?
No, unless you switch on Allow negative stock in the module settings, and even then only for corrections you make. Orders never take more than the warehouses hold, except for two existing cases: a paid express checkout that was over stock (the order is flagged for review), and a POS register set to allow negative sales.