Overview
Assembly Orders in Luminous have two closely related behaviors that work together: the Auto Split feature (which assigns BOM component quantities to specific storage locations and lots) and the inventory reservation system (which commits those quantities as "pending" the moment an order becomes active). Understanding both helps you anticipate how your available inventory numbers will change as an Assembly Order moves through its lifecycle.
How Auto Split Works
When you create or edit an Assembly Order, the Auto Split checkbox controls how Luminous assigns each BOM component to storage locations.
Auto Split ON (default)
When you select a BOM, choose a Warehouse Group, and enter a Planned Quantity, Luminous automatically scans every storage location in that Warehouse Group that holds the required component. It then:
- Sorts locations by lot expiry date — earliest-expiring stock is pulled first (FEFO order).
- Creates one line per location — consuming as much of each location's available quantity as needed until the full planned quantity is covered.
- Handles shortfalls gracefully — if a location runs out before the quantity is satisfied, Luminous moves on to the next location. If stock across all locations is still short, the remaining quantity is appended to the last line.
- Creates a single unassigned line if no stock exists — so you can fill in the location manually.
The result is that a single BOM component may appear as multiple lines, each pointing to a different location and/or lot.
Auto Split OFF
Luminous picks the single location with the largest available quantity for each component and assigns the entire planned quantity to that one line — even if that location does not have enough stock to cover it.
Recomposing lines
Any time you change the Planned Quantity, Warehouse Group, or BOM on an open Draft order with Auto Split ON, Luminous automatically refreshes the component lines from current inventory. You can also click the Recompose from Current Inventory button at any time to force a fresh location/lot assignment without changing any other settings.
Note: Toggling Auto Split after lines already exist triggers an immediate recomposition — your existing line assignments will be replaced.
Inventory Reservation Lifecycle
The location and lot assignments created by Auto Split (or entered manually) directly determine which stock gets reserved when the order becomes active.
Assembly Order statuses
| Status | Inventory effect |
|---|---|
| Draft | No reservation — inventory is visible and available to other orders |
| Issued | Component quantities are added to pending inventory — stock is reserved |
| In Progress | Same as Issued — pending reservation remains in effect |
| Paused | Same as Issued — pending reservation remains in effect |
| Completed | Pending reservation is released and actual on-hand quantities are deducted |
| Rolled Back | Pending reservation is reversed — stock returns to available |
What happens when you move to Issued
The moment an Assembly Order transitions from Draft to Issued, Luminous reserves the component stock by recording each line's quantity as pending at the specific warehouse location (and lot, if applicable) assigned to that line. This reduces the available quantity shown for each component SKU, signaling to the rest of the system that this stock is committed.
- Reservations apply only to Assembly Orders (not Disassembly Orders).
- Each line is reserved individually, tied to the exact location and lot set on that line.
- If an order moves between Issued, In Progress, and Paused, the reservation stays in place throughout.
When reservations are released
- Order completed: The pending reservation is cleared, and the component quantities are permanently deducted from on-hand inventory.
- Order rolled back or deleted: The pending reservation is reversed and the stock becomes available again.
- Order moved back to Draft: The pending reservation is rolled back — lines revert to their Draft state and the stock is freed.
Practical tips
- Finalize location assignments before issuing. Once an order moves to Issued, the reserved quantities are locked to the locations on each line. If inventory positions have changed, use the Recompose from Current Inventory button while the order is still in Draft.
- Check available stock warnings. If the total reserved quantity exceeds physical stock at a location, Luminous will surface a warning when you attempt to complete the order — it will not silently over-commit.
- Lot-tracked operations: Leaving Auto Split ON is strongly recommended because it pre-fills FEFO-ordered lot assignments, which become the lots deducted when the order completes.
For a deeper look at the Auto Split toggle behavior and the Recompose button, see the related article: How does the Auto Split feature work in Assembly Orders, and when should I use it?