Fill Rate
The fraction of demand satisfied immediately from on-hand inventory — measured by line, unit or order value depending on the contract.
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How does Fill Rate apply to your shop floor?
Pick your industry and scale — Ask V5 rewrites the definition in your context, gives a worked example, and shows what V5 does on day one.
01What it is
The fraction of demand satisfied immediately from on-hand inventory — measured by line, unit or order value depending on the contract. 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 Fill Rate 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 Fill Rate
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
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Fill Rate sits inside this topic cluster in our glossary. Every neighbour is one click away.
Material requirements planning, BOM explosion, net requirements, scheduling and demand signals that drive what the floor makes next.
Want to see how Fill Rate could fit into your own records and workflows? Explore the related V5 pages or talk to our team about what applies to your operation.