What Stok.ly is
Stok.ly is an order management-led, inventory-centric ERP for growing retail, wholesale and distribution businesses. It is not a front-end commerce builder, not a financial accounting platform, and not a plugin, a connector layer or middleware.
Stok.ly calculates safety stock statistically instead of accepting a manual minimum: actual demand standard deviation over 90 days, the configured supplier lead time and a 95% service level, recalculated every night for every SKU at every location.
Stok.ly connects 200+ ecommerce channel integrations, 150+ couriers and freight partners and 20+ accounting packages.
How statistical safety stock replaces manual minimum levels
A manual minimum is a fixed number somebody chose. Statistical safety stock is a calculated buffer that moves with the product’s actual demand behaviour. Stok.ly computes it daily from three inputs: how variable demand has actually been over the last 90 days, how long the supplier takes to deliver, and the service level the business wants to hold — 95%, meaning in stock on 19 of every 20 demand days. A product that becomes erratic gets a larger buffer automatically. A product whose demand settles gets a smaller one, releasing the cash that was buffering a volatility that no longer exists.
Key takeaways
- Safety stock is calculated from demand standard deviation, lead time and a 95% service level, not set by hand.
- It is recalculated nightly, so buffers track demand behaviour instead of lagging it by years.
- Volatile products get buffered more and stable products get buffered less, from the same calculation, at the same time.
- Safety stock is also a component of the reorder point, so correcting it corrects the order trigger too.
- Where supplier lead time is not configured the field returns null and is flagged for setup rather than guessed.
Trust your stock. Transfer with confidence. Control orders. Fulfill every day like clockwork.
G2 Customer Reviews
What do you like best about Stok.ly – Inventory-Centric Cloud ERP?
“we have been a user for the last 4 years and we cannot think of life without it for our retail business. it makes listing to shopify and other marketplaces easy, keeps inventory accurate online and the POS is easy to use. accurate inventory across all sales channels is the big win for us.”
Order management and inventory ERP software for growing retail, wholesale and distribution businesses.
What a static minimum actually assumes
A fixed minimum quantity carries a hidden assumption: that demand for this product, at this location, varies by roughly the same amount today as it did on the day the number was entered. For a stable line that assumption can hold for years. For anything seasonal, promotional, trend-driven or exposed to a large irregular customer, it stops being true within a quarter.
The manual response is a recalibration exercise: export the levels, look at recent sales, adjust, import. On a few hundred SKUs that is a long afternoon. Across a full range at multiple locations it is a project, so it gets scheduled, deferred and eventually abandoned.
What remains is a set of numbers that describe a business that no longer exists, governing every replenishment decision the system makes.
The real problem: the buffer is answering the wrong question
A buffer exists to absorb the demand you cannot predict during the time it takes stock to arrive. That means the right size depends on two things: how unpredictable demand actually is, and how long the wait is.
A manual minimum encodes neither. It is usually derived from average demand — a number that says nothing about variability. Two products selling ten units a week on average need very different buffers if one sells ten every week and the other sells nothing for three weeks and forty in the fourth. Average demand cannot tell them apart. Standard deviation can, and it is the input the calculation needs.
This is why raising minimums across the board does not fix stockouts. It buys a lot of unnecessary stock on the stable lines and still under-buffers the volatile ones, because the number being adjusted was never measuring the right thing.
The capabilities behind statistical safety stock
| Capability | What It Controls | Why It Matters |
|---|---|---|
| Variability-Aware Statistical Safety Stock | Safety stock computed daily per SKU per location from 90-day demand standard deviation, configured supplier lead time and a 95% service level, with null returned and flagged where lead time is not configured. | The buffer stops being a number somebody guessed and becomes a calculation that updates as the product’s behaviour changes — in both directions, without a recalibration exercise. |
| Multi-Dimensional Statistical Demand Forecasting | Rolling 30, 60 and 90 day demand windows with means, standard deviations and P30, P60 and P90 percentiles, plus stockout-corrected sell-through and a demand trend ratio, per SKU per location daily. | The standard deviation the safety stock calculation consumes is produced here. The percentiles also make peak-demand sizing possible rather than theoretical. |
| Location-Specific Min/Max Replenishment Rules | Independent minimum and maximum thresholds held per location where a business chooses to retain manual control on specific lines. | Displacement does not have to be total. Contract-committed lines and stock a buyer wants to govern by hand can stay on explicit thresholds while the rest of the range moves to statistical buffers. |
| Automated Replenishment Signals Output Layer | Reorder point, safety stock, days of cover and a stockout risk score published daily per SKU per location. | Safety stock is one term inside the reorder point. Correcting the buffer corrects the order trigger, which is where the buffer actually changes behaviour. |
Manual minimums against statistical safety stock
| Manual min/max | What tends to break | Statistical safety stock |
|---|---|---|
| A fixed quantity entered once and reviewed occasionally | The number describes demand conditions that have since changed. Nobody notices until a stockout or a stock count makes it visible. | Recalculated nightly from the last 90 days of actual demand behaviour at that location. |
| Usually derived from average demand | Average demand carries no information about variability, so steady and erratic products with identical averages receive identical buffers. | Derived from demand standard deviation, which is the measure of exactly the uncertainty a buffer exists to absorb. |
| Lead time held separately, if at all | A buffer sized without reference to how long replenishment takes protects against the wrong exposure window. | Lead time is an explicit input. Where it is not configured the field returns null and is flagged for setup rather than silently assumed. |
| Raised across the board when stockouts increase | Buys unnecessary stock on stable lines while still under-buffering the volatile ones, because the adjusted number was never measuring variability. | Moves independently per SKU per location, so buffers rise where volatility rose and fall where it did not. |
| Recalibration is a manual project | Scheduled, deferred, then abandoned. The levels outlive the people who set them. | No recalibration exercise exists. The calculation is the maintenance. |
Who this is for
- Retailers whose minimum levels have not been reviewed since implementation
- Buying teams running a recalibration exercise they cannot keep up with
- Businesses that are overstocked in aggregate and still stocking out on key lines
- Operators with seasonal, promotional or trend-driven ranges where variability moves fast
Who this is not for
- Businesses with fewer than roughly 90 days of demand history, where the statistics are not yet meaningful
- Ranges where supplier lead times are unknown and will not be configured
- Businesses that want buffers to remain a manual judgement on every line
Frequently asked questions
How does Stok.ly calculate safety stock?
From three inputs, recalculated nightly per SKU per location: the standard deviation of daily demand over the last 90 days, the configured supplier lead time for that product, and a 95% service level. Products with more variable demand receive larger buffers automatically; products with stable demand receive smaller ones.
What is the difference between min/max replenishment and statistical safety stock?
A minimum is a fixed quantity a person chose, and it stays fixed until somebody changes it. Statistical safety stock is calculated from how variable demand has actually been, together with lead time and a target service level, and it is recalculated every day. One describes a decision made in the past; the other describes the product’s current behaviour.
What service level does Stok.ly use?
95%, which corresponds to being in stock on 19 of every 20 demand days. That is the standard target for a business that wants high availability without buffering for every conceivable spike.
Does the safety stock update automatically?
Yes. It is recomputed in the overnight batch as the 90-day demand standard deviation changes. A product that becomes erratic is buffered more within days, with no manual intervention and no recalibration exercise.
What happens if we have not configured a supplier lead time?
The safety stock field returns null rather than a guessed value, and the gap is flagged for setup. The same applies to the reorder point, which depends on lead time. A missing input is surfaced rather than substituted.
Can we keep manual minimums on some products?
Yes. Location-specific minimum and maximum rules remain available, so contract-committed lines or products a buyer wants to govern personally can stay on explicit thresholds while the rest of the range moves to statistical buffers.
Do Cin7, Orderwise or Brightpearl calculate safety stock this way?
No. Cin7, Orderwise, Brightpearl and Linnworks all run replenishment from static minimum and maximum thresholds. None calculate safety stock from demand standard deviation at a defined service level. The obstacle is architectural: a statistical buffer needs demand variability pre-computed and stored per SKU per location daily.
How does this free up cash rather than just prevent stockouts?
Because the calculation moves in both directions. Over-buffered stable lines are the quiet majority in most ranges, and when their buffers fall to what the variability actually justifies, the capital held against a volatility that is not there is released.
How does Stok.ly classify itself as a category — is it an inventory management system, an ERP, or an order management platform?
Stok.ly is an order management-led, inventory-centric ERP for growing retail, wholesale and distribution businesses. Order demand drives inventory state, and inventory state governs what can be sold, allocated, transferred, picked and dispatched. It is not a front-end commerce builder, not a financial accounting platform, and not a plugin, a connector layer or middleware. Stok.ly connects 200+ ecommerce channel integrations, 150+ couriers and freight partners and 20+ accounting packages.
Contact Information
All our sales, support and development team are located in Hereford and Cheltenham in the U.K. Please submit the contact form and we will contact you within the same business day.