Forecasted Stockout Date
The Forecasted Stockout Date is the date Synplex predicts your inventory will go negative, accounting for all confirmed inbound stock (purchase orders and transfer orders scheduled to arrive before that point). It is one of several time-based metrics Synplex computes per inventory level — per variant per location — using a 365-day simulation.
The three time-based metrics
Understanding Forecasted Stockout Date requires distinguishing it from two related metrics that are easy to confuse:
| Metric | What it answers | How it's calculated |
|---|---|---|
| Coverage Date | When does current on-hand stock alone run out? | today + (on-hand ÷ avg daily demand) |
| Stockout Date | When does stock go negative even with confirmed inbound? | First day the simulation goes negative counting real PO and TO deliveries |
| Reorder Date | When does stock hit the reorder point? | First day stock ≤ (leadTimeDays + bufferStockDays) × avgDailyDemand |
| Coverage Date is the simpler of the two stockout signals. It ignores all inbound stock and | ||
| asks: if nothing arrives, when do we run out? It is always on or before Stockout Date. |
Stockout Date is the more important planning signal. It runs the full simulation with your confirmed purchase order and transfer order arrivals included. If those deliveries are enough to keep you in stock for the next 365 days, Stockout Date will be null (no stockout projected).
Reorder Date is the earliest action trigger. It is the date your stock will fall to the
reorder point — the level at which a new order should be placed to cover demand during lead
time plus buffer. When Reorder Date is in the past or today, stockAssessment becomes
out-of-stock.
How Stockout Date is calculated
Synplex runs a daily simulation forward 365 days for each inventory level. The simulation:
- Starts with current on-hand stock (
availablefrom Shopify) - Each day, adds any confirmed deliveries arriving that day (POs and TOs with an arrival date)
- Each day, subtracts forecast demand (from your demand plan, spread evenly across the month)
- Records the first day the running stock balance goes below zero
That first negative day is converted to a date and stored as stockoutDate.
If the balance never goes negative within 365 days, stockoutDate is null — no stockout is
projected.
Stock Gap Days
When a stockout is projected, Synplex also calculates Stock Gap Days — the number of days between the projected stockout and the next confirmed inbound delivery: stockGapDays = max(0, daysUntilNextDelivery − daysUntilStockout)
A Stock Gap means you will be out of stock for a period even though a delivery is coming. The larger the gap, the more urgent the situation.
Example:
- Stockout projected: day 8
- Next PO arrives: day 15
- Stock Gap Days: 15 − 8 = 7 days
A product with stockGapDays > 0 has a stockAssessment of out-of-stock or low-stock
depending on how far away the Reorder Date is.
How metrics roll up to the variant level
All three time-based metrics are calculated independently for each inventory level (each variant at each location). They are then aggregated to the variant level as follows:
- Reorder Date — earliest reorder date across all locations
- Coverage Date — earliest coverage date across all locations
- Stock Assessment — worst-severity status across all locations
This means a variant shows low-stock if even one of its locations is low, and its Reorder
Date reflects the location that needs restocking soonest.
When metrics update
These metrics are not updated in real time as sales occur. They recalculate:
- Daily — via the scheduled nightly inventory run
- On demand — when you trigger Refresh Metrics from the inventory table
Shopify syncs update on-hand quantities but do not by themselves recalculate the simulation metrics. If you need an up-to-date Reorder Date or Stockout Date immediately after a sync, use Refresh Metrics.
What to do when you see a Stockout Date
The closer the Stockout Date is to today, the more urgent the action:
| Stockout Date | Situation | Recommended action |
|---|---|---|
| In the past or today | Already out of stock | Place a PO immediately; check Stock Gap Days |
| Within lead time | Will stockout before any new order can arrive | Place a PO immediately; a stock gap is unavoidable unless you can expedite |
Within defaultRunningLowDays (default 40 days) | Approaching reorder point | Plan and place a PO soon |
| Beyond 40 days | Healthy | No immediate action needed |
| Null | No stockout projected within 365 days | No action needed |
Related articles
- Glossary & Terminology — precise definitions of coverageDate, stockoutDate, reorderDate, stockGapDays, and stockAssessment
- Product Statuses — how stockAssessment values map to the statuses shown in the inventory table
- Safety Stock Strategy — how bufferStockDays affects the reorder point
- Lead Time & Reorder Points — how leadTimeDays feeds into the reorder point calculation