Reorder point for slow moving products: a few units a month
If a SKU sells three or four units a month, the usual reorder maths goes soft, because most weeks show no sales at all. This page is about setting a reorder point for slow-moving products, and how Restoc builds one from a sales velocity window of 7, 14 or 30 days and the lead time you supply per SKU.
The SKU that sells three a month, and goes quiet when it is gone
Your top forty SKUs pay the rent. You know their numbers by feel. The other few hundred are the long tail: a colour nobody asks for until someone does, a size that moves twice a quarter, the accessory that attaches to a kit you still sell.
The tail is where the quiet damage happens. A hero SKU hitting zero shows up the same day, because the orders stop and someone emails you. A slow seller hitting zero looks exactly like a slow seller that is fine. Nothing drops, nothing complains. Six weeks later you notice the line has been unavailable the whole time, and the restock takes as long as your supplier takes.
The job in front of you is not forecasting. It is narrower than that: knowing when to reorder. A full planning system will model demand for you and charge accordingly, and most stores running 200 to 2,000 SKUs do not need the model, they need the trigger. The honest state of play is usually a spreadsheet, rebuilt every few months, accurate on the twenty SKUs you cared about on the day you built it.
The decision is narrower than it looks too. For each slow SKU you need one number, the stock level at which you place the next order, and something that watches for the crossing while you are doing everything else.
Why slow movers break the usual reorder maths
A reorder point is velocity multiplied by lead time, and velocity is the part that misbehaves on a quiet SKU.
Most windows read zero
A SKU selling three a month sells nothing in a typical week. Measure it over seven days and you get zero units a day most of the time, then a spike the week someone buys two. The number is not wrong, it is just too short a sample to mean anything.
Averages hide the lump
Stretch the window out and the average smooths, but the demand itself stays lumpy. Nothing, nothing, nothing, four at once. An average of 0.1 units a day describes the month well and describes any given Tuesday badly.
Lead time does the heavy lifting
When velocity is small, the reorder point lives or dies on lead time. A slow seller with a 60-day supplier wait needs real cover sitting on the shelf. The same slow seller with a local supplier who ships in three days barely needs any. Lead time is the input only you can supply, and on the tail it matters more than the sales figure does.
So the practical answer for slow movers is: take the longest velocity window you have, give it a lead time you actually believe, and then let something watch the crossing rather than trying to eyeball a few hundred quiet SKUs by hand.
How Restoc sets a reorder point on a quiet SKU
- Connect the store once
Restoc installs through Shopify OAuth and is built to pull inventory levels and sales history through webhooks plus a scheduled sync job. It is a web app, with no mobile app and no browser extension.
- Set the velocity window to 30 days
The window is configurable at 7, 14 or 30 days. For a tail of slow sellers, 30 days is the steadiest read available, and it is the longest window Restoc offers.
- Enter the lead time for each slow SKU
Lead time is a merchant input, per SKU. The tail is usually where lead times differ most, because the slow lines often come from the supplier you order from least.
- Let the engine compute the point
The reorder point calculation is a tested pure function over your velocity window and your lead time. Its tests cover the cases a long tail produces: zero-sales SKUs, high-variance history, SKUs with fewer days of history than the window, and SKUs already at zero stock. In each case it returns a defined, non-negative number rather than nothing.
- Get told when a SKU crosses
An alert fires when a SKU crosses its reorder point, by email, and by Slack webhook on Growth and above, delivered through an idempotent background job so one crossing is one message.
- Order from the weekly list
A weekly reorder report lists the SKUs below their reorder point with a suggested order quantity, viewable in the app and exportable as CSV. On a long tail this is the useful shape: a short list of the quiet lines that need attention this week.
What the window choice does to a SKU selling three a month
| Velocity window | What it reads on a slow seller | Trade-off |
|---|---|---|
| 7 days | Most weeks contain no sale, so the window often reads zero a day and then jumps on the week a sale lands | Useful on a fast mover, too short a sample on a quiet one |
| 14 days | A single sale in the window reads as roughly 0.07 units a day, two sales doubles it | Still swings hard on anything selling under one a week |
| 30 days | Three sales in the month read as roughly 0.1 units a day, the steadiest number available here | The longest window offered, and it lags a genuine step change in demand |
What this gives a store with a long tail
A number on every SKU, not just the busy ones
A reorder point per SKU from your velocity and your lead time, computed for the whole tracked catalogue rather than the handful you would get round to by hand.
Zero-sale weeks do not break it
The calculation is tested against zero-sales SKUs, short history and stock already at zero, and returns a defined, non-negative reorder point in each case.
One alert per crossing
Alerting is built on an idempotent background job, so a SKU crossing its point does not turn into a repeating email every time the job runs.
Days of inventory remaining, per SKU
The dashboard shows current stock, days of inventory remaining and reorder status per active SKU, which is how you spot a tail line drifting down before it bottoms out.
A per-SKU window where the tail needs one
The velocity window is store-wide, and Pro adds custom reorder rules: a per-SKU sales velocity window override, for the lines that want a different read from the rest of the store.
A weekly list you can hand to a supplier
The weekly report exports as CSV with suggested order quantities, so a scattered tail order becomes one file instead of an afternoon of cross-checking.
Plans, by how big the tail is
Starter, $29 a month
Up to 200 tracked SKUs, one location. Reorder point per SKU, the 7, 14 or 30 day velocity window, email alerts, the weekly reorder report with CSV export, and the days-of-inventory dashboard. Billed by Shopify on your Shopify invoice. $290 a year if paid yearly, which is ten months' price for twelve.
Growth, $59 a month
Up to 1,000 tracked SKUs, five times Starter's capacity and enforced at sync time, plus Slack alerts through an incoming webhook alongside email. Everything in Starter. $590 a year if paid yearly.
Pro, $99 a month
Up to 2,000 tracked SKUs and custom reorder rules, a per-SKU sales velocity window override, on top of everything in Growth. $990 a year if paid yearly. Every plan carries a 60-day free trial.
Questions
Can Restoc set a reorder point for a SKU that sells two units a month?
Yes. The reorder point is computed per SKU from your chosen velocity window and the lead time you enter, and the calculation is tested against zero-sales SKUs and short sales history, so it returns a defined, non-negative number rather than failing on a quiet line. On a SKU that slow, the lead time you supply does most of the work.
Which velocity window should I pick for slow-moving products?
30 days is the steadiest of the three available, because a 7-day window on a SKU selling a few units a month reads zero most weeks. The window is set store-wide, and Pro adds a per-SKU override if your fast and slow lines want different reads. There is a sibling page on choosing between 7, 14 and 30 days.
What does a slow mover with no sales in the window show?
A SKU with no sales in the selected window has no measurable velocity, so the calculation still returns a defined, non-negative reorder point rather than failing or returning nothing. The tests on the calculation cover exactly this case, and the dashboard carries current stock, days of inventory remaining and reorder status for every active SKU.
Will I be buried in alerts if most of my catalogue is slow?
Alerts fire when a SKU crosses its reorder point, and delivery runs through an idempotent background job, so one crossing produces one message rather than a repeat each time the job runs. The weekly reorder report is the other half of this: one list of everything currently below its point, with suggested order quantities.
Do slow SKUs count against the tracked-SKU limit?
Yes. The limits are 200 tracked SKUs on Starter, 1,000 on Growth and 2,000 on Pro, enforced at sync time, and a slow seller counts the same as a hero. A long tail is usually the reason a store needs Growth or Pro rather than Starter.
Does Restoc add safety stock for variable demand?
No. The reorder point comes from your sales velocity window and your lead time, and there is no separate safety-stock multiplier. Some merchants pad a lumpy SKU by entering a lead time a few days longer than the supplier quotes. The safety stock page in this pillar covers the thinking.
Can I try it before paying?
Every plan is declared with a 60-day free trial, and the trial is built so that at least one full weekly reorder cycle completes before any first charge, which matters on a slow tail where a single week tells you very little. Restoc is on a waitlist today, so sign up and we will say when installs open.