Min/Max Reorder Point Monitor: Catch Low Stock Before It Stops the Line

The problem this kills

The cheapest way to stop a production run cold is to run out of a two-dollar consumable. The gasket, the label stock, the cleaning solvent, the bolt — nobody notices it's getting low until the line operator opens an empty bin mid-shift. Then it's a panic call to the buyer, an expedite fee, and a run that sits idle while a courier drives across town.

The maddening part is that this is completely predictable. Every item has a level where you should reorder — the reorder point — set high enough to cover the supplier's lead time. The trouble is that nobody is sitting there every morning comparing on-hand stock against the reorder point for hundreds of items. So it gets checked when someone remembers, or when it's already too late. And when you do reorder, it's easy to make it worse: you order again for something that already has a purchase order in transit (double-ordering), or you order an odd quantity the supplier won't accept because it ignores the minimum order quantity (MOQ) or the case/pallet order multiple.

You don't need an MRP system to fix this. You can build a reorder-point monitor yourself, this afternoon — one that checks every item every day, accounts for what's already on order, and suggests the right quantity to bring you back up to max.

What you'll build

An internal web tool your buyers and stockroom leads log into. You import your item stock snapshot (the on-hand quantity export you already have) and your min/max/reorder settings — the reorder point, the max or economic order quantity, the supplier, and the lead time per item. Optionally you import your open purchase orders so the tool knows what's already on the way.

The tool then does the watching for you: it flags every item where on-hand (plus on-order) is at or below the reorder point, and for each flagged item it suggests an order quantity that brings you back up to max — rounded to honor the MOQ and the order multiple, and netted against anything already on order so you don't double-buy. The result is a clean suggested reorder list, sorted by urgency, that the buyer reviews on screen. The buyer ticks which lines to convert, approves the selection, and clicks once to export a requisition CSV in the exact columns your purchasing system wants — plus a daily low-stock email via Resend so nothing falls through the cracks.

What's inside the Implementation Plan

The downloadable plan is a single markdown file you paste into an AI coding agent. It opens by interviewing you about your own inventory and purchasing process — how your stock export is shaped and what you call each field, where your min/reorder/max settings live, how you encode supplier and lead time, whether you track on-order stock, your MOQ and order-multiple rules, and your requisition export columns — and then it reads a short spec back for your thumbs-up before it builds anything. That's the difference between a tool shaped to your SKUs and reorder conventions and a generic template you have to fight.

From there it walks the agent through the data model (items, stock snapshots, reorder settings, on-order, suggested reorder lines, audit), the importer, the reorder-check engine that flags items at or below their point and computes the suggested quantity, the MOQ / order-multiple rounding, the on-order netting that prevents double-ordering, the buyer review-and-approve screen, the requisition export, and the daily Resend low-stock email. Every step ends with a ready-to-copy prompt. There's a full "No API yet?" path: stock + settings CSVs in, requisition CSV out — you never have to touch your ERP's API to ship.

The governance it includes (this is the point)

A reorder suggestion becomes real money the moment it turns into a PO, so the controls are the product. The plan builds them in: a login so only your team can use it; row-level security so each organization only ever sees its own items and reorder lists; a complete audit trail of who imported what, who flagged it, who approved which lines, and when; a hard human-approval gate so a suggested line can't become a requisition export until a buyer ticks it and signs off; and a duplicate guard keyed on item plus reorder-suggestion date so the same item can't be suggested — and ordered — twice in one cycle. Nothing gets exported until a person has reviewed the quantities and the on-order offset.

Who it's for

Buyers, stockroom leads, and production planners who are responsible for keeping consumables and raw materials in stock. If you can read your own stock export and explain what "reorder point" means for your items, you can build this — no developer required.

You've got this — open the plan, paste the first prompt, answer a few questions about how your stock and settings are shaped, and you'll watch your first low-stock list turn into a clean, approved requisition this afternoon.