Kalkulator sigurnosne zalihe i točke ponovne narudžbe (potražnja i rok isporuke)

Procijenite sigurnosnu zalihu i točke ponovne narudžbe iz varijabilnosti potražnje i roka isporuke.

Podržava procjenu min/max, nisku/srednju/visoku razinu usluge i izračune po razdobljima za sezonsku potražnju.

Unosi, URL-ovi za dijeljenje i lokalna pohrana ostaju u ovom pregledniku i ne šalju se na poslužitelj.
Započnite čak i ako ne znate standardne devijacije
Jasno vidite pretpostavke i logiku izračuna
Pregledajte razdoblja visoke i niske potražnje po periodu
Brzo ponovno upotrijebite rezultate kopiranjem i URL-om za dijeljenje

How to use

  1. Choose the demand average and how you want to enter variability.
  2. Enter the lead time average and variability, then choose a service level.
  3. Turn on seasonality if needed and enter multiple periods with separate demand values.
  4. Copy the result or save it as a shareable URL for the next reorder-point review.

Uzorak

Standard case

Input

Average demand 120/day, demand 80 to 160, average lead time 7 days, lead time 5 to 10 days, service level 95%

Output

Reorder point 1,103, safety stock 263, average demand × lead time 840

With seasonality

Input

Peak season 180 (140 to 240), normal season 120 (80 to 160), slow season 70 (50 to 95), average lead time 7 days, lead time 5 to 10 days

Output

The peak season is highlighted as the highest reorder-point period, and each period shows its own safety stock and reorder point.

Brzi izračun sigurnosne zalihe i točke ponovne narudžbe uz varijabilnost roka isporuke

Pregledajte sigurnosnu zalihu i točku ponovne narudžbe na istom zaslonu.

Alat pretpostavlja da su varijabilnost potražnje i varijabilnost roka isporuke neovisne te koristi normalnu aproksimaciju.

Više razine usluge povećavaju i sigurnosnu zalihu i točku ponovne narudžbe.

Što više varira rok isporuke, sigurnosna zaliha postaje važnija.

Što unijeti kada varijabilnost nije poznata

Starting with a min/max estimate is usually good enough.

If you have historical data, enter the average and standard deviation directly.

If you are unsure, start with Medium (95%) as the service level.

The rough low / medium / high option is useful for an initial comparison.

Rječnik

Sigurnosna zaliha

Dodatna zaliha koja se drži kako bi se apsorbirala varijabilnost potražnje ili roka isporuke.

Točka ponovne narudžbe

Razina zalihe na kojoj trebate naručiti sljedeću pošiljku.

Razina usluge

Ovdje znači približnu vjerojatnost da neće doći do nestašice tijekom roka isporuke kada naručujete na točki ponovne narudžbe.

Varijabilnost roka isporuke

Koliko se vrijeme od narudžbe do zaprimanja razlikuje u danima ili tjednima.

Kako izračun radi

  • σDL = sqrt((μL × σD²) + (μD² × σL²))
  • Safety stock SS = z × σDL
  • Reorder point ROP = (μD × μL) + SS
  • Min/max estimate: σ ≈ (max - min) ÷ 4 (assuming about 95% coverage)

Česta pitanja

I do not know the standard deviation.

You can estimate it from min and max values. The tool treats that range as roughly 95% of the usual spread and estimates the standard deviation automatically. That is often practical enough to start with.

What does service level mean here?

Here it is the approximate probability of not stocking out during lead time when you reorder at the reorder point. Higher targets usually increase safety stock.

My item has seasonal demand.

You can calculate multiple periods separately. Enter average demand and variability for busy, normal, and slow periods, then compare each period's safety stock and reorder point.

I have the reorder point. Will this tool also tell me order quantity?

No. This tool estimates when to reorder. Order quantity still depends on MOQ, lot size, storage capacity, cost, and ordering policy.

Is this the same as fill rate?

No. The service level in this tool is an approximation of cycle service level. It does not calculate fill rate directly.

Obavijest

  • These results are only a planning guide. You still need to consider MOQ, order multiples, storage space, budget, and obsolescence risk.
  • The tool assumes demand variability and lead time variability are independent and uses a normal approximation.
  • For intermittent demand or frequent supply disruptions, a different model may fit your operation better.