The short answer
Reorder level planning replenishes an item whenever its free stock falls to a preset point — set high enough to cover demand during the lead time, plus a safety buffer. It is the simplest, most robust way to keep steady-demand items in stock without running a full planning calculation. You set a reorder point per item; the system watches stock; when the balance drops to the point, it raises a replenishment order. No forecast, no BOM explosion — just a threshold that says "order now, or you will run out before the next delivery arrives".
Reorder point planning is the companion to MRP, not a rival — it handles the long tail of consumables while MRP plans demand-linked components. This guide sits under the pillar, what is production planning software?, and complements how MRP works and the item-level settings in MRP planning parameters.
The reorder point formula
The reorder point answers one question: what stock level, if I order now, leaves me just enough to last until the new stock arrives? That is demand during the lead time, plus a buffer:
The formula exposes exactly what makes a reorder point right or wrong: the demand rate and the lead time. Understate either and the point is too low, so you order too late and stock out during the wait. This is why lead time is a planning parameter that has to be maintained per item, and why demand that is trending — a festival build-up, a new customer — should push the point up, not sit on a stale average.
Safety stock — the buffer inside the point
Averages lie in a useful way: real demand and real lead times vary around them, and half the time they run higher. Safety stock is the buffer that absorbs that variability so a spike in demand or a late delivery does not become a stockout. It is a component of the reorder point, not a separate mechanism — the point is lead-time demand plus safety stock.
How much safety stock is a trade-off: more buffer means fewer stockouts but more cash tied up in inventory and more risk of ageing. The right level depends on how variable demand and lead time are and how costly a stockout is — a line-stopping component earns a fat buffer, a cheap easily-sourced consumable a thin one. The discipline is to set it deliberately per item rather than letting it drift, because an unexamined safety stock is either quietly starving service or quietly hoarding cash.
How much to order
The reorder point decides when; a separate rule decides how much. The common choices:
- Fixed reorder quantity. Always order the same batch — simple, and often set to a supplier pack or an economic order quantity that balances ordering cost against carrying cost.
- Order-up-to-level. Order enough to bring stock back up to a target maximum, so the quantity varies with how far stock has fallen — the min-max approach below.
- Rounded to a constraint. Force the quantity up to a minimum order quantity, a supplier multiple or a pack size, exactly as lot sizing does in MRP.
Min-max control
The most common reorder scheme in practice is min-max: two levels per item, a minimum that is the reorder point and a maximum that is the target stock. When free stock hits the minimum, you order enough to return it to the maximum. It is self-correcting — a big drawdown triggers a big order, a small one a small order — and it caps inventory at the maximum, so you never over-stock. Min-max is what most reorder-level dashboards implement, and it is well suited to the wide tail of stores and consumables a manufacturer keeps.
| Level | Meaning | What it protects |
|---|---|---|
| Minimum (reorder point) | Lead-time demand + safety stock | Against stockout |
| Maximum (order-up-to) | Target stock after replenishment | Against over-stock |
| Order quantity | Maximum − free stock at trigger | Restores to target |
Reorder point versus MRP
Reorder point and MRP answer the same question — when to replenish — for different kinds of item, and a good plant uses both:
| Aspect | Reorder point planning | MRP |
|---|---|---|
| Demand type | Independent, steady | Dependent on a production plan |
| Trigger | Stock falls to a threshold | A planning run against demand and BOM |
| Looks ahead? | No — reacts to current stock | Yes — time-phased future demand |
| Best for | Cheap, high-turn consumables, stores | Demand-linked components and materials |
| Effort | Low — set and forget | Higher — needs BOM and plan |
Trying to force every item through MRP over-engineers the consumables; trying to force every item onto a reorder point ignores the future demand MRP can see. The art is classifying items — demand-driven components to MRP, steady consumables to reorder points — so each gets the lightest control that keeps it in stock.
The reorder-level dashboard
Reorder points are only useful if something watches them. A reorder-level dashboard continuously compares every item's free stock against its reorder point and lists those below, with a suggested purchase requisition for each — the auto-PR mechanism that is the day-to-day safety net between formal MRP runs. Instead of a buyer scanning stock reports, the system surfaces exactly what needs ordering and proposes the quantity, so replenishment happens on time without a planning cycle. This is precisely the planning engine's continuous complement to the periodic run.
Seasonal and festival demand
A static reorder point assumes steady demand, but Indian markets are anything but steady around festivals and seasons — a Diwali or wedding-season peak can multiply offtake for weeks. A reorder point set on an annual average will trigger too late for the peak and too much after it. The practical discipline is to raise reorder points and safety stock ahead of a known peak and lower them afterwards, so the buffer grows before demand does rather than after the stockout. A reorder-level dashboard is where a planner does this deliberately — nudging the threshold up for the season and letting the auto-PR suggestions build the buffer in advance.
How Fast Planning automates reorder
Fast Planning Software — built by Improsys in Pune under the Fast Technology brand, cloud or on-premise — runs a live reorder-level dashboard alongside the MRP engine. Each item carries its reorder level as a planning parameter, and the dashboard continuously lists items whose free stock has fallen below their point, proposing a purchase requisition for each — replenishment that keeps working between formal planning runs. Because it reads the same live stock that MRP nets against and that production consumes, the reorder signal reflects real inventory, not a stale snapshot. Planners raise thresholds ahead of seasonal peaks, and the auto-PR suggestions build the buffer before demand arrives — one shared platform for both demand-driven and threshold-driven replenishment.
Frequently asked questions
What is a reorder level?
A reorder level, or reorder point, is the stock quantity at which you trigger replenishment. When free stock falls to the reorder point, it is time to order more — set so that the stock still on hand is enough to cover demand during the replenishment lead time, plus a safety-stock buffer for variability. Above the point you do nothing; at or below it you raise a purchase requisition or work order. It is the simplest, most robust replenishment signal for items with steady demand.
How is the reorder point calculated?
The reorder point is average demand during the lead time plus safety stock: Reorder point = (average daily demand × lead time in days) + safety stock. The first term covers expected consumption while you wait for the order to arrive; the safety stock covers the demand and lead-time variability that averages hide. For example, 20 units a day with a 10-day lead time and 50 units of safety stock gives a reorder point of 250. Get the lead time or demand rate wrong and the point is wrong.
What is the difference between reorder point and safety stock?
Safety stock is the buffer you hold against variability; the reorder point is the trigger level that includes it. Safety stock answers how much extra to keep so that a demand spike or a late delivery does not cause a stockout; the reorder point adds that buffer on top of expected lead-time demand to decide when to order. Safety stock is one component of the reorder point, not a substitute for it — the point tells you when, the safety stock tells you how much protection is built in.
When should I use reorder point planning instead of MRP?
Use reorder point planning for items with steady, independent demand where a threshold is enough — cheap, high-turn consumables, standard fasteners, packaging, general stores. Use MRP for items whose demand is dependent on a production plan, where you want to plan components against the actual finished goods that will consume them rather than a static level. Most plants run both: MRP drives demand-linked components, reorder points top up the long tail of consumables between planning runs.
What is min-max inventory control?
Min-max is a common reorder scheme with two levels: a minimum (the reorder point) and a maximum (the target stock). When free stock hits the minimum, you order enough to bring it back up to the maximum, so the order quantity varies with how far stock has fallen. It is simple, self-correcting and well suited to items managed by a reorder-level dashboard. The minimum protects against stockout; the maximum caps how much inventory you carry.
How does a reorder-level dashboard help?
A reorder-level dashboard continuously compares every item's free stock against its reorder point and lists those that have dropped below, with a suggested purchase requisition for each. It is the day-to-day safety net between formal MRP runs: instead of a planner manually scanning stock, the system surfaces exactly what needs replenishing and proposes the order. In seasonal Indian markets it is also where a planner raises reorder points ahead of a festival peak so the buffer grows before demand does.