Ecommerce automation
Low stock alert automation
Running out of a best seller is expensive, and often avoidable: the stock level was visible for weeks, but nobody looked at the right moment. Low stock alerts tell the right person when to reorder, before it is too late. The useful kind does not fire at a fixed number of units for every product; it compares stock with how fast each item sells and how long the supplier takes to deliver, and sends a short daily list rather than a stream of individual warnings.
This page covers alerts in and around an online store. Reorder logic inside inventory software is covered on the inventory management software pages.
Illustrative diagram
- Recent sales
- Daily rate
- Days of cover
- Compare with lead time
- Reorder list
- Buyer orders
Days of cover, not fixed numbers
Ten units left is plenty for a slow seller and a crisis for a fast one. A more useful measure is days of cover: current stock divided by average daily sales over a recent period. Compare it with the supplier's lead time plus a margin for variation and for the time it takes you to place an order. When cover falls below that figure, the item should appear on the reorder list. Recalculate sales rates regularly so seasonal changes are reflected.
Exclude days when the item was out of stock from the sales rate, or demand will be underestimated.
Same stock, different urgency
| Product | Situation |
|---|---|
| Fast seller, 20 in stock, sells 5 a day | 4 days of cover; supplier takes 10 days: urgent |
| Steady seller, 20 in stock, sells 1 a day | 20 days of cover; supplier takes 10 days: plan |
| Slow seller, 20 in stock, sells 1 a week | Months of cover: no action |
What the daily reorder list should show
Per product
- Stock and days of cover
- Supplier and lead time
- Stock already on order
Context
- Sales trend over recent weeks
- Upcoming promotions
- Minimum order quantities
Action
- Suggested quantity
- Link to create a purchase order
- Mark as ordered
Account for stock already ordered
An alert that ignores stock already on order sends buyers chasing products they have dealt with. Include open purchase orders and their expected dates in the calculation, and let buyers mark an item as ordered so it drops off the list until the delivery is due. If a delivery date passes without arrival, the item should return to the list with a note.
Watching promotions and sudden spikes
Promotions, press coverage or a social post can multiply sales overnight, and a sales rate based on recent weeks will lag. For products in a promotion, or when daily sales jump well above the usual rate, send an immediate alert rather than waiting for the daily list. Agree in advance who decides whether to reorder urgently, limit the promotion or switch to pre-order.
Example: one list each morning
Illustrative example — not a client case study
Situation: A store's owner checks stock levels by eye every few days and still runs out of popular items.
- Days of cover is calculated nightly from sales and stock, with each supplier's lead time recorded.
- A morning email lists items below their threshold, with stock on order and a suggested quantity.
- Items in a promotion trigger an immediate alert if sales jump.
What this shows: Reordering became a ten-minute morning task, and stock-outs on best sellers fell. This example is illustrative.
Where should alerts be calculated?
In an inventory or reorder app
Suits you when
- Many products and suppliers
- You want purchase orders and lead times in one place
Watch out for
- Subscription
- Check how it calculates sales rates
A scheduled report or workflow
Suits you when
- A modest range
- Stock and sales are in the store
Watch out for
- Lead times and stock on order must be stored somewhere
- Keep the calculation documented
Seasonal products
For seasonal ranges, recent sales can mislead: rates rise sharply before a season and fall after. Use last year's sales for the same period as a guide where you have them, set alerts earlier ahead of peaks to allow for longer supplier lead times, and switch alerts off for items you do not intend to reorder once the season ends. Buyers' judgement matters most here; the list should inform it, not replace it.
Measuring results
Track stock-outs on best sellers, days out of stock and urgent reorders before and after alerts, and review thresholds where items still run out.
Bundles and components
Base alerts on components rather than bundles, since a bundle runs out when any component does. Include bundle sales in each component's sales rate.
Questions about low stock alert automation
What is days of cover?
Current stock divided by average daily sales.
Why not alert at a fixed stock level?
The same number means different urgency for fast and slow sellers.
Should alerts include stock on order?
Yes, so buyers do not chase items already ordered.
How are promotions handled?
With immediate alerts when sales jump well above the usual rate.
How should alerts be delivered?
As one daily list, with immediate alerts only for spikes.
Can purchase orders be drafted automatically?
Yes, as suggestions a buyer reviews before sending.
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