What is Unserviceable Demand in Production Planning?
Quick Answer: Unserviceable demand is forecasted demand that cannot be fulfilled by available inventory. When this occurs, Moselle may display a negative inventory value in a period before your order is scheduled to arrive — this is expected behavior and signals a projected stockout gap.
What Does "Unserviceable Demand" Mean?
Unserviceable demand is the portion of your projected sales demand that exceeds available inventory during a given period. It represents units that customers are expected to want but that you won't have on hand to fulfill.
In Moselle's production planning table, this manifests as a negative Ending Quantity value in one or more periods — most commonly in the periods immediately before a purchase order is scheduled to land.
Why Am I Seeing a Negative Value Before My Order?
A negative value in the Ending row means your projected sales during that period will draw inventory below zero before your incoming order replenishes stock.
This typically happens when:
Lead time creates a gap — Your order is on the way, but it won't arrive until a future period. In the meantime, forecasted demand continues to consume inventory.
Safety stock is insufficient — The buffer stock set on a SKU or at the plan level isn't large enough to cover demand during the lead time window.
Demand is higher than expected — A spike in the forecast exceeds what current stock can cover before the next order arrives.
No order has been placed yet — The plan shows the gap as negative to signal that an order is needed.
Don't ignore negative values. A negative Ending Quantity is Moselle's way of flagging a potential stockout. Review these periods and adjust your order quantities or timing to close the gap.
How to Read the Production Plan Table
When you expand a SKU row in the production planning table, you'll see these detail rows:
Starting Stock Level
Inventory at the beginning of the period
Projected Sales
Forecasted units expected to sell that period
Suggested Order
Mo's recommended buy quantity (shown in blue)
Ending Quantity
Starting stock minus projected sales, plus any orders landing that period
A negative Ending Quantity means: projected sales exceed the starting stock for that period, and no order is scheduled to land in time to cover the gap.
Example: Negative Value Before an Order
Imagine a product with the following situation:
February Starting Stock: 50 units
February Projected Sales: 80 units
Purchase Order Landing: March (due to a 6-week lead time)
In this case, February Ending Quantity = 50 − 80 = −30 units. This negative value represents the 30 units of unserviceable demand — sales Moselle forecasts you'll lose because inventory runs out before the March order arrives.
The negative value disappears in March once the order lands and replenishes stock.
How to Resolve Unserviceable Demand
Increase Safety Stock
If negative values are recurring for a SKU, consider increasing the Safety Stock setting on that item. Safety stock adds a buffer to absorb demand fluctuations and lead time variability.
Navigate to the item in your Catalog, open the item details, and update the Safety Stock custom attribute.
Place or Adjust an Order
Update the Order quantity in the affected period or an earlier period so the inventory lands before the stockout occurs. The Ending Quantity will recalculate automatically.
Once enough inventory is ordered to cover the gap, the negative value will resolve and the Ending Quantity will return to zero or positive.
Frequently Asked Questions
Is a negative Ending Quantity a bug or an error?
No — it is intentional. Moselle displays negative values to clearly flag periods where demand is projected to exceed supply. It is a signal to take action, not an error in the system.
Will the negative value affect my actual inventory records?
No. The production plan is a forward-looking projection only. Negative values exist in the plan to help you spot and prevent future stockouts — they do not alter your current inventory levels.
Why does Moselle still show a negative value even though I have an order placed?
If your order lands after the period with the deficit, the negative value will persist in the earlier period. The order only resolves the gap in the period it is scheduled to arrive. To eliminate the negative value, the order needs to land in or before the period where demand exceeds supply.
Can I adjust lead times to fix this?
Lead times reflect real-world supplier timelines and should not be changed just to make the numbers look better. Instead, use accurate lead times and plan your orders earlier to account for them. You can update lead times on individual items via the Transit Lead Time custom attribute in the Catalog.
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Manage Your Production PlanAdd Your ConstraintsGenerate OrdersLast updated