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Reorder level and safety stock: setting a level that actually works
· Invenva
The question is not how much you have, it is when to order. The two numbers that decide it, the formula and a calculator for safety stock and your reorder level, and what to check in an app.
Safety stock and reorder level calculator
Reorder when stock falls to the reorder level.
Reorder level = average sold per day × lead time + safety stock, which is the same as most sold in one day × longest lead time
Safety stock = most sold in one day × longest lead time − average sold per day × lead time
The question is not how much, it is when
Knowing you have four left is only half an answer. Four is comfortable if the supplier delivers tomorrow and you sell one a week. Four is an emergency if you sell six a day and the next delivery is Thursday. The number on the shelf means nothing until you put it next to how fast it leaves and how long it takes to come back.
This is why a plain stock sheet stops being enough. It tells you the position and not the risk, so the shop still runs out of the fast movers while money sits in the slow ones.
The two numbers that decide it
The first is how much you sell in a normal week. Not your best week, not your worst: the ordinary one. The second is the lead time, meaning how many days pass between placing an order and putting the goods on the shelf, counting the days the supplier is shut and the day you actually get round to ordering.
Multiply the daily sales by those days and you have the amount that will leave while you wait. Add a little on top for the week that goes better than usual, and that total is your reorder level: the level at which you should be ordering, not the level at which you panic.
What to check in an app
Three things separate a reorder level that works from one you end up ignoring.
- Can you set it per product? One threshold for the whole shop is wrong for almost every line in it.
- Does it reach you, or does it wait in a screen you have to remember to open?
- Can you turn the alert into an order without retyping the list?
Doing it in Invenva
Every product can carry its own reorder level, called Low stock alert in the app, and it is one of the optional rows on the item, so lines that do not need one do not get a box to fill. Anything at or under its level shows up in red on the Stock screen and gathers under the Low stock filter, so the whole exposure is one tap rather than a scroll.
When a product crosses into low stock the app tells you rather than waiting: a banner if you have it open, a notification if you do not, and the same message to everyone on the team. Crossing the line is the moment, so it is announced once and not every time the number moves.
From there a new order puts what is low at the top of the list, in red, so the list you would have written by hand is a few taps away. You adjust the quantities, send the order, and when the goods arrive you check them in against it. The demo has products sitting under their level and needs no account.