The Inventory Reorder Point: "We're Out" Is a Math Error, Not Bad Luck

Every stockout has the same anatomy: the item had a usage rate, the supplier had a lead time, and nobody multiplied them. The reorder point is that multiplication — and once every item has one, running out requires ignoring a flag instead of forgetting a feeling.

How it works

• The Reorder Board — daily usage × (lead time + safety days) = the trigger. Flags compare it to on-hand PLUS on-order: REORDER NOW, Soon, or quiet. The order-up-to column suggests the quantity — a one-screen min-max system
• The Stockout Math — fourteen "run to the supply house" events plus rush freight cost the sample $3,420 a year; the cushion that prevents them costs $570 to carry. Six dollars back per dollar of shelf — and the flip side: near-zero-usage items with same-day suppliers have a reorder point of "don't"
• The Ritual — count A-items weekly (ten minutes survives; everything-weekly dies by week three); the two-bin trick for small parts — the reorder point implemented in plastic; the truck is part of the count; and the two-minute postmortem: every stockout means one input lied — usage, lead time, or the count. Find which

Built for

Shops, salons, makers, restaurants — any business where "we're out" currently gets discovered mid-job instead of computed a week early.

What you get

One .xlsx file, four tabs, instant download. Excel, Google Sheets, Apple Numbers, LibreOffice. No macros, no subscription.