The plain-language guide
How much safety stock to keep.
Safety stock and your busy-day cushion look like the same thing. They're not. One covers a bigger sales day than expected. The other covers a supplier running late. Size them the same way and one side is left uncovered.
The short answer
Safety stock is not the busy-day cushion from the forecasting guide. That number covers you if you sell more than expected. Safety stock covers you if your supplier is late or short, after you've already ordered. Count it in days, not units: a day count still makes sense next month even after your sales change. A fixed quantity doesn't.
Two jobs, one word
Keep a busy-day cushion but no safety stock, and a late truck catches you. Keep safety stock but no busy-day cushion, and a better-than-expected Saturday catches you instead. One buffer only covers half the risk. Both look like the same pile of extra stock on the shelf, so it's easy to think one is doing the job of two.
Count it in days
A quantity goes stale as soon as your sales change. 40 spare patties was three days' worth in a slow month, and one day's worth once Friday got busy. A percentage sounds precise and isn't: 15% of a three-day delivery window is half a day's buffer, and the percentage won't tell you that. A day count will. It means the same thing no matter how much you're selling this week, and you can say it out loud and check it against reality.
When to reorder
Take the burger stall's patty supplier: a 2-day lead time. Add 3 days of safety stock — a fair starting point for a supplier that mostly shows up on time — and you should reorder once you have 5 days of stock left, counting what's on hand and what's already on the way. Order before that point and the new delivery lands with your safety stock intact. Order after it and you're already spending the buffer while the new order is in transit.
Tracking what's already on the way, day by day, is exactly what the transit guide's day rule is for.
Try it with your numbers
5
days of stock left — reorder at or below this
Picking your number
- 2–3 days for a supplier that's reliable and delivers often.
- 4–7 days for a supplier that's slow to respond, delivers rarely, or has let you down before.
- 0–1 days for anything that spoils fast enough that the extra stock itself becomes the loss.
- Different items, different numbers. A box of wraps and a tray of lettuce shouldn't get the same one.
Don't fix the wrong buffer
A stockout after a busy Saturday is a busy-day problem, not a safety-stock problem. Raising safety stock won't fix it — it just ties up more cash and, for anything perishable, adds spoilage. Fix the buffer that failed, not the other one.
Where ForeFlux picks up
ForeFlux keeps a safety-stock number for every item — 3 days by default. Change it per item, or for the whole account, in Profile. The moment an item has fewer days of stock left than that number, it's flagged urgent, whether or not the busy-day forecast agrees. Lead time plus safety stock is the point where "order it soon" becomes "you should have already ordered it."
Every number here is yours to change. The default fits a supplier that behaves normally. If yours doesn't, change it in Profile.
Questions owners ask
Past the basics.
How is safety stock different from the busy-day cushion?
Different problems. The busy-day cushion covers you if you sell more than expected. Safety stock covers you if your supplier is late or short, after you've already ordered. An item can be forecast perfectly and still run out if the truck doesn't show — that's what safety stock is for.
What's a reasonable number to start with?
2 to 3 days for a supplier that's reliable and delivers often. Higher for a supplier that's slow or has let you down before. Lower — sometimes zero — for anything that spoils before a buffer would ever get used.
Does more safety stock mean I order less often?
No. It changes when you need to reorder, not how much or how often. A bigger number just moves that point earlier.
What's a thoughtful approach to setting reorder points that accounts for variability?
Set the reorder point from the slow case, not the average. Take average daily sales times the supplier's longest realistic lead time, then add safety stock sized for how much your sales and your supplier actually swing. Measure both swings from the last month: the gap between an average day and your busiest, and the gap between promised and actual delivery. Perishables get a smaller cushion, because the cost of being wrong on the high side is the full price of the item. Shelf-stable items can carry more. Revisit the number monthly, because lead time drifts. ForeFlux recomputes the deadline per item as sales and lead times change, and every number stays yours to override.
Get the buffer right, per item
Know what you need, before you need it.
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