Short answer. Consumption is read from the movement ledger, per product and depot, over a written window, recent weeks weighing more. The supplier lead time is measured, order to reception, as a median over the last receptions, never the supplier’s promise. The reorder point is consumption during that lead time plus a safety stock set by the manager, following the common formula; it is compared every night with available, stock minus reserved plus on order. When available drops below the point, a quantity is proposed to cover a written period, rounded to the supplier’s packaging. The proposal is grouped by supplier, with its minimum order, its lead time, the total and the week’s budget; the manager decides line by line, and every deviation is recorded with its reason. The purchase order is numbered, sent, and creates an expected reception; the real reception, scanned, feeds the measured lead time of the next proposal. Events, promotion, closure, season, are entered and adjust expected consumption.
This guide is for the wholesaler and distributor ordering from ten suppliers every week, the shopkeeper with several outlets, the pharmacy or parapharmacy that must never run out of its staple products, and the founder based in France who wants to see on Monday what goes on order and why. It does not repeat how to keep stock right, described in the stock guide, nor how to receive by lot, described in the traceability guide; it describes what reads those two ledgers to decide what to order, and it extends our software engineering page.
When to order, and how much: one product, one depot
The figure follows one product at one depot. Everything it reads already exists: ledger issues and past receptions.
Consumption. Eight weeks of issues, between 110 and 160 units, read from the ledger of the stock guide; the average, weighted towards recent weeks, gives about 19 units a day. Exceptional issues, a customer emptying the shelf, are flagged and can be excluded by the manager. Lead time. Ten days, the median of this supplier’s last six receptions, from the date the order was sent to the date of the reception scan; the supplier’s promise, five days, does not enter the computation. Reorder point. Consumption during the lead time, 193, plus a three-day safety stock, 60, that is 253; safety protects against demand fluctuations, and its size is the manager’s decision, raised to five days before summer.
The date. Available, 420 in stock minus 60 reserved, that is 360, falls by 19 a day and crosses the point on 16 November: that is the day the line appears in the proposal, not when the shelf is empty. The quantity. Cover target: four weeks beyond the point, 793; minus available, 433; rounded to the case of four, 436. The manager can change it, and the application recomputes the stock-out date and the cover. Product, sales, lead times and thresholds are a constructed example; packagings come from the product record guide.
«The lead time is measured on past receptions, not promised by the supplier; consumption is read from the ledger, not guessed.»
The replenishment cycle, in six beats
The computation is the accented beat; the first two read, the last three decide, send and learn.
Read consumption and measure lead time: two readings of existing data, no entry. Compute the point: every night, by a job of the background jobs guide, for every tracked product and depot; available counts reserved and on order, so that a product already ordered is not ordered twice. Propose: lines below the point are grouped by supplier, with quantity, rounding, minimum order, total and budget.
Decide and send: the manager accepts, cuts, removes or adds, line by line, and every deviation from the proposal is recorded with its reason; the purchase order is numbered and sent by e-mail and WhatsApp, following the notifications guide; who may send beyond the budget follows the roles guide. Receive and learn: an expected reception is created, the reception scan matches it, the gap is recorded, and this reception’s real lead time enters the median of the next proposal. The supplier’s invoice is then read through the AI invoice reading guide and matched to the purchase order.
Six real situations, and what the application does
Every row is a sentence heard in a warehouse, and the answer is a measure, not a better memory.
Out of stock on the fastest mover: the reorder point is compared with available every night, and the proposal arrives before the stock-out, not after. Too much stock on the slow mover: the quantity is computed by written cover, and cover after delivery is shown per line; six months stand out. The supplier promises 5 days, delivers in 12: lead time is measured on receptions, as a median per supplier, and that is what enters the point.
Minimum order not reached: the minimum is on the supplier record, and the application proposes the lines closest to their point to reach it, rather than anything. Promotion next week: the event is entered by the manager, and expected consumption for the period is adjusted; the same mechanism serves closures and season. Nobody knows what is on order: on-order counts in available, and the expected reception is visible with its date. The portal of the B2B ordering guide reads the same available to promise a delivery.
Monday’s proposal for one supplier
The figure shows the screen the manager opens on Monday: one proposal per supplier, one decision per line.
Six products from the same supplier. For each: available, point, proposed quantity, packaging rounding, cover after delivery, amount, and the decision. Four lines are accepted; margarine is cut by half because a promotion ends on the 20th, and the manager writes why; vinegar is removed because the product is end of life in the product record, and the application flags it; 1-litre oil appears for information only, it is above its point.
Before sending, four checks: the supplier’s minimum order, written on its record, is met; the total after decisions; the expected delivery, computed with the median lead time; the share of the week’s purchasing budget, a cap set by the manager. The purchase order is sent at 9:12, numbered, and an expected reception is created for 26 November; an agent built following the back-office agent guide may prepare the proposal and chase the supplier without confirmation, never send an order beyond the budget. Quantities, amounts and dates are a constructed example.
«The proposal is computed every night and grouped by supplier; the manager decides line by line, and every deviation is recorded with its reason.»
Replenishment, in five layers
Consumption and lead time are the accented layer: they are measures, not memories.
Data. The movement ledger, reservations, open supplier orders, dated receptions, and the supplier record with its measured lead time, minimum and packagings; nothing is entered twice. Consumption and lead time. Issues per product and depot over a written window, recent ones weighted, exceptional ones flagged; median lead time per supplier on receptions; recomputed every night. Rules. Safety stock, cover period, upcoming events, budget; per category or per product; written by the manager, changed without development.
Proposal. Point compared with available; quantity, rounding, minimum; grouped by supplier; decision line by line with recorded deviation. Order and loop. Purchase order sent, expected reception, scan, gap, real lead time fed back; stock-outs, days of cover, overstock and lead-time gaps per supplier in the manager’s dashboard; orders and receptions go to accounting through the integration guide. Dated products also follow the rules of the traceability guide: no short lot is ordered for a customer who requires sixty days.
Automating replenishment in 2027, in weeks
Seven weeks, the first without code, and two for the proposal, because it is the screen the manager opens every Monday.
- What the manager sees: on Monday, one proposal per supplier with cover, minimum, total and budget; every day, lines dropped below the point; every week, stock-outs and overstock.
- What the buyer no longer does: count shelves, guess the lead time, retype a purchase order, order twice a product already on order.
- What is measured: stock-outs per product, days of cover, overstock in days, real lead time per supplier against promised, reception gaps.
Week 1, rules: which categories are tracked, which safety stocks, which cover periods, which budget, and supplier records with minimum and packagings; with the manager and the buyer. Week 2, consumption and lead time: ledger reading, window and weighting, median lead time per supplier computed from past receptions, compared with promises so the manager sees the gap. Weeks 3 and 4, proposal: reorder point, available, quantity, rounding, minimum, grouping by supplier, decision screen with recorded deviations.
Week 5, order and reception: numbered purchase order sent, expected reception, scan, gaps, real lead time fed back. Week 6, events: promotions, closures, season, expected consumption adjusted, end of life excluded. Week 7, measurement: stock-outs, days of cover, overstock, lead-time gaps per supplier, Monday review. Old order histories, if they exist in a file, are taken over with the import guide to measure lead time from the second week; a pharmacy with several outlets, as in the pharmacy guide, follows the same cycle with one point per outlet.
- Where does the reorder point come from?
- From the common formula: consumption during the supplier lead time, plus a safety stock. Consumption is read from the movement ledger, lead time is measured on past receptions, and safety is the manager’s decision, per category or per product.
- Why not take the lead time promised by the supplier?
- Because it is often wrong, and a reorder point computed on too short a lead time produces a stock-out every time. The measured lead time is the median of the last receptions, from sending the order to the reception scan; the manager sees the gap with the promise, supplier by supplier.
- Does the manager keep control?
- Yes: they decide line by line, accept, cut, remove or add, and every deviation is recorded with its reason. Safety stocks, covers, budget and events are theirs; the application computes and proposes, it does not send without them.
- How are promotions and season handled?
- Through entered events: a promotion, a closure, a season adjust expected consumption for their period, and the proposal takes it into account. A past exceptional issue can be excluded from the average.
- And the supplier’s minimum order?
- It is written on the supplier record with the packagings. If the proposal does not reach it, the application proposes the lines closest to their point to complete it, and the manager chooses; the total and the budget are checked before sending.
- Is a long history needed to start?
- A few weeks of ledger are enough for consumption; for lead time, old orders and receptions, if they exist in a file, are taken over to measure from the second week. Without history, the manager enters a starting lead time, replaced by the measure from the first receptions.
- How long to set this up?
- Seven weeks in the typical calendar, the first without code and two for the proposal. A company that already has the movement ledger and scanned receptions takes less; one that orders from memory and receives without scanning takes all seven, because data comes first.