Stock Shortages
A stock shortage occurs when a sale is recorded for more units than you have available in lot-tracked inventory. Partsemble doesn't block these sales — it processes them, flags the shortage, and uses a fallback costing method for the shortfall.
Why Sales Aren't Blocked
Sales often come from your accounting system, where invoices are created regardless of what Partsemble knows about your inventory. Blocking a sync because of a stock mismatch would break the connection between your accounting data and your production data. Instead, Partsemble processes every sale and clearly flags when lot-tracked inventory couldn't fully cover it.
Common reasons for shortages include sales being synced before the corresponding production build is recorded, timing gaps between your accounting system and Partsemble, or inventory that was never received through the lot tracking system.
How Shortages Are Handled
When a sale line requires more quantity than available lots can provide, Partsemble:
-
Consumes all available lots using FIFO, just like a normal sale. These units are costed at their actual lot costs.
-
Flags the shortage. The sale line is marked with
has_stock_shortage = Trueand records the shortage quantity — the difference between what was sold and what lots could cover. -
Costs the shortfall at weighted average cost. For the units that couldn't be fulfilled from lots, Partsemble uses the product's current weighted average cost (WAC) as the unit cost. This provides a reasonable cost estimate when specific lot costs aren't available.
Example
You sell 8 Industrial Enclosures, but only 5 units exist in lot-tracked inventory across two build lots:
| Source | Qty | Unit Cost | Total Cost |
|---|---|---|---|
| LOT-ASM-001 (FIFO) | 3 | $145.00 | $435.00 |
| LOT-ASM-002 (FIFO) | 2 | $148.00 | $296.00 |
| Shortage (WAC) | 3 | $146.50 | $439.50 |
| Total | 8 | $1,170.50 |
The sale line shows a shortage flag and the margin calculation uses the blended cost of $146.31 per unit.
Identifying Shortages
Sale lines with stock shortages are visually flagged in the sale detail view. You can see which lines were affected and how much of each line was covered by lots versus the WAC fallback.
Resolving Shortages
Stock shortages are informational — they don't require action to "fix" in Partsemble. However, they often indicate a workflow gap worth addressing. If you're seeing frequent shortages, consider syncing sales less frequently (to give production time to catch up), ensuring all production builds are recorded before syncing sales, or checking that receiving is capturing all incoming inventory.
If the shortage occurred because a build or receipt was recorded after the sale synced, the shortage remains on that sale — Partsemble doesn't retroactively reassign lots to past sales. Future sales will consume the newly available lots normally.
Impact on Margins
Margins on sale lines with shortages are still calculated, but they're partially based on WAC rather than pure FIFO lot costs. This means the margin may be less precise for those lines. The shortage flag makes it clear which margins are affected.