Min/Max Replenishment
A simple replenishment policy that triggers an order up to Max whenever stock falls to Min — common for indirect spares and slow-moving SKUs.
01What it is
A simple replenishment policy that triggers an order up to Max whenever stock falls to Min — common for indirect spares and slow-moving SKUs. The discipline matters because every other warehouse metric — fill rate, days of supply, working capital, shift roster, replenishment workload — is downstream of how well demand is predicted and how cleanly that prediction flows into stock policy. A warehouse that runs Min/Max Replenishment well treats it as a continuous loop: clean history, statistical baseline, judgemental override, signed-off S&OP plan, executable replenishment policy, and measured forecast accuracy that closes back on the model.
- History is cleaned of stockouts, promos and one-offs before modelling.
- Statistical baseline is the starting point — not a guess from sales.
- Judgemental overrides are documented, signed off, and tracked for bias.
- Forecast accuracy (MAPE, bias) is measured every cycle and fed back to the model.
- Stock policy parameters are derived from the forecast — not set in spreadsheets and forgotten.
02Typical planning flow
| Stage | Activity | Owner |
|---|---|---|
| Cleanse | Strip outliers from history | Planning |
| Model | Statistical baseline | Planning |
| Override | Judgement, promo, new product | Sales / marketing |
| S&OP | Cross-functional sign-off | Executive |
| Policy | Safety stock, ROP, EOQ | Planning |
| Execute | Replenishment orders | Buying / WMS |
| Measure | MAPE, bias, fill rate | Planning |
03Execution and controls
- Refresh safety-stock parameters on the same cadence as the forecast — not annually.
- Track forecast bias by product family — persistent bias signals a process problem, not a model problem.
- Tie S&OP plan to executable warehouse capacity — promises that exceed dock or labour capacity are not plans.
- Recalculate EOQ when input costs change materially — frozen EOQs become wrong quickly.
- Report fill rate by channel and customer tier — averages hide important misses.
04Common mistakes
- Forecasting at the wrong level — too high hides SKU mix, too low is statistically meaningless.
- Sales overrides accepted without governance — forecast becomes sales target plus a wish.
- Safety stock set once and forgotten — every demand shift erodes service level.
- S&OP signed off but never reconciled to actual — no learning loop.
- Fill rate measured at order level only — line-level customer pain is invisible.
05Cross-industry examples
- Grocery — short shelf life forces tight forecast accuracy; daily replenishment cycles.
- Fashion — high obsolescence risk, season-based planning, life-cycle curves.
- Industrial spares — long tail, intermittent demand, Croston or bootstrap methods.
- Pharma — regulated supply continuity drives high service-level targets.
- Subscription DTC — known customer base, deterministic forward demand.
06How V5 Ultimate handles Min/Max Replenishment
Frequently asked questions
Q.What is MAPE?+
Mean Absolute Percentage Error — the headline forecast accuracy metric, calculated as the average of |actual − forecast| / actual.
Q.Service level vs fill rate?+
Service level is the probability of no stockout in a cycle; fill rate is the fraction of demand satisfied immediately. They are related but not the same.
Q.Is EOQ still relevant?+
Yes — adapted with container, MOQ and shelf-life constraints — but rarely used as the raw Wilson formula.
Q.How often should S&OP run?+
Monthly with a weekly demand and supply review in between; faster-moving sectors run weekly cycles.
Q.Can AI replace statistical forecasting?+
ML methods improve accuracy for high-volume SKUs with rich features; they do not replace the cleanse-override-S&OP process around them.
Primary sources
Further reading
V5 Ultimate ships with the Min/Max Replenishment controls already wired in — audit trail, e-signatures, validation evidence. Free trial, no credit card, onboard in days, not months.
