Where Product Inventory Lives
Product inventory is reviewed from two places. The Inventory module shows the operating view across products and locations. The product detail page shows the product-specific view for one SKU, including thresholds, location balances, transactions, serials, bins, and related setup.
Inventory Overview is the cross-product operating view for stock health, balances, alerts, and value warnings.
Understand the Core Quantities
- On hand: the physical quantity at a location.
- Allocated: stock reserved for open orders or work that has not been fulfilled yet.
- Available: stock that can still be promised. This is usually on hand minus allocated.
- On PO: quantity expected from open purchase orders that has not been received yet.
- Reorder point: the threshold that helps purchasing know when to buy more.
- Value: inventory value based on stock quantity and cost history.
Use The Product Inventory Tab For One SKU
The product detail Inventory tab is the best place to answer questions about one product. It has its own location filter, so support can review all locations or one location without changing the global header location used elsewhere in Arcus.
The product Inventory tab shows one SKU across locations, value, run rates, FIFO layers, transactions, and Recost actions when a value row needs repair.
- All locations: use this to understand product-level availability, allocations, value, and demand pressure.
- One location: use this when a warehouse, bin, pick, receive, or count question is location-specific.
- Independent location scope: the product tab filter is separate from the global header location, so you can audit one product without changing the rest of the app.
- Inventory by Location: compare on hand, allocated, available, on PO, reorder point, average value, and total value by location.
- Run rates: compare recent daily demand over 30, 90, 180, and 365 days.
- Transactions: audit the movements that changed this product, with filters for type, status, and location.
- Active FIFO layers: review the remaining cost layers available for future outbound movement.
- FBA breakdown: review marketplace fulfillment stock context when FBA quantities exist for the product.
Read Supply And Demand On The Product
The product Inventory tab includes a product-specific Supply and Demand panel. Use it when a support case or planner asks whether the SKU is actually at risk, not just whether it has low stock today.- Available: current available quantity in the selected scope.
- Current demand: open demand that still needs supply.
- Blended daily demand: recent demand rate used for projection math.
- Lead time: the buying or planning lead time used for the projection.
- Days until stockout: the estimated time before available stock is exhausted.
- Reorder quantity and reorder date: suggested buying guidance based on demand and thresholds.
- Stockout risk: the risk label for the current projection. If Arcus says there is not enough data, treat the label as unknown instead of safe. The chart can show supply, demand, and reorder point over the selected horizon. If the panel shows a warning, retry state, or unknown-data message, document that context before escalating or changing reorder setup.
How Inventory Changes
Inventory should move through the workflow that matches the real-world event. That keeps stock, cost, purchasing, fulfillment, and accounting aligned.- Receive Inventory: add standalone stock when it is not tied to a purchase order.
- Receive a PO: add stock from a purchase order and keep GRNI and vendor billing aligned.
- Inventory Adjustment: correct a counted quantity, damage, loss, or setup issue with a reason.
- Warehouse Transfer: move stock from one location to another without pretending it appeared or disappeared.
- Fulfillment: consumes stock when orders are packed, shipped, or marked fulfilled.
- Return processing: can bring stock back, send it to inspection, or dispose of it depending on disposition.

Inventory Transactions shows the audit trail for stock movement, balance changes, source links, and cost context.
Receiving and Cost Basis
Receiving creates stock and cost history. If stock is from a purchase order, receive it from the PO workflow. Use standalone receiving only when the stock truly is not tied to PO receiving.
Standalone receiving is available, but PO-driven inventory should be received from the purchase order workflow.
Adjustments and Corrections
Use adjustments for counted corrections, damaged stock, lost stock, setup cleanup, or other inventory corrections. The adjustment reason and notes should explain why the quantity changed.
Adjustments should explain the real-world reason for the correction and preserve cost context where required.
FIFO Cost History
Arcus uses FIFO cost behavior for inventory valuation. Receiving creates cost layers. Fulfillment and other outbound movements consume the oldest eligible cost layers first. That gives accounting a traceable cost basis for inventory value and cost of goods sold.
FIFO layer detail helps explain which cost layer supported an outbound inventory movement.
Fix Negative Product Value Safely
A negative value warning means the balance value for a product or location needs review. Use the product Inventory tab to decide whether the source workflow is wrong or whether the balance row should be recomputed from the FIFO ledger.- Open the product detail page.
- Open Inventory.
- Check whether the warning is on all locations or one location.
- Review recent receives, adjustments, fulfillment, returns, and manufacturing consumption.
- Open FIFO layer detail for outbound transactions when cost consumption looks suspicious.
- Correct bad source records when the receipt, adjustment, or purchase cost is wrong.
- Use Recost only when the ledger is right but the balance row is stale.
Planning Reorders
Inventory settings and demand signals feed purchasing work. Reorder points, safety stock, open purchase orders, and demand pressure help operators decide what to buy and when.
Supply and Demand turns product balances and demand signals into buying pressure and reorder guidance.
Common Blocks
- Available is lower than expected: stock may be allocated to open orders.
- On PO does not match expectation: review open purchase orders and what has already been received.
- Supply and Demand says not enough data: review transactions, recent demand, open POs, and lead time before treating the product as low risk.
- Wrong warehouse appears on the product tab: check the product Inventory tab location dropdown. It is intentionally separate from the global header location.
- Value looks wrong: review recent receiving, adjustments, and FIFO layer detail before posting a shortcut correction.
- Recost is missing: the row may not have negative value, or your role may not allow inventory adjustments.
- Adjustment is blocked: the counted quantity, unit cost, reason, or permission may be missing.
- Receiving is blocked: product, location, quantity, unit cost, or PO guidance may need review.
- Product cannot be fulfilled: stock, serials, bins, kit components, payment holds, or approval holds may be blocking fulfillment.

