Promise-Date / Available-to-Promise Calculator
Build an internal tool that turns "when can we ship it?" into a realistic, defensible promise date - checking finished stock, the production queue, lead times, and work-center capacity before a planner confirms it.
A logged-in tool where sales/CS enters an item and quantity, sees the earliest realistic ship date computed from stock, queue, lead times and capacity, and a planner confirms it before it's quoted - with a full audit trail and CSV export.
Before you start
- A free Vercel account
- A free Supabase account
- A free Resend account
- Your stock, production-queue, and capacity data in a Google Sheet or CSV
The problem this kills
Sales is on the phone and the customer wants a date. So they pick one - usually the one that wins the order. Then it lands on the production floor, where the work center is already three weeks deep, the raw material isn't in, and that "two weeks" was never real. Now you're choosing between a late shipment, an expedite that eats the margin, and an angry customer.
The honest answer to "when can we ship it?" is sitting in four places that nobody checks at the same time: how much finished stock is on the shelf, what's already in the production queue, the lead time to make more, and how much capacity each work center actually has. Pulling all four together by hand, mid-call, isn't realistic - so people guess.
This tool does that math for you and makes the guess go away.
What you'll build
A small, private web app for your team. Someone in customer service or sales support types in an item and a quantity (and the date the customer is asking for). The tool checks:
- Finished stock first - if you can ship it from the shelf, it says so.
- Then the make-to-order path - it walks the open production queue, applies the lead time, respects each work center's capacity, skips weekends and holidays, and adds your safety buffer.
It hands back the earliest realistic ship date with a plain-language explanation of how it got there ("80 from stock today, 120 made by July 9"). Then - and this is the important part - a planner reviews and confirms that date before it can be quoted to the customer. Every confirmed promise is logged, and you can export the whole log as a CSV in exactly the columns your ERP or order system expects.
What's inside the Implementation Plan
The plan is a complete, paste-and-go runbook for an AI coding agent (Claude Code). You don't write code - you paste, answer questions, and approve.
It opens by interviewing you about your actual business - your items and how you name them, how you track stock and your production queue, your work centers and their real capacity, your lead times, your weekend/holiday rules, and your messy exceptions (rush orders, partial shipments, split lots). It reflects a short tailored spec back to you and waits for your thumbs-up. The tool it builds fits your shop floor, not a generic template.
From there it builds step by step: the database, the login, the data import, the promise-date engine tuned to your rules, the planner approval screen, the audit log, and the CSV export - each step ending with a ready-to-copy prompt.
The governance it includes (this is the point)
This isn't a spreadsheet macro. It's built like a real internal system:
- Login so only your team can open it.
- Row-level security so each organization only ever sees its own data.
- A human-in-the-loop approval gate - the tool drafts a promise date; a planner reviews and approves before anything is committed or quoted.
- A complete audit trail - who calculated what, who confirmed it, and when.
- Duplicate guards keyed on your quote/order reference, so the same order can't be promised twice by accident.
Who it's for
Customer service reps, sales support, and production planners who are tired of promising dates the floor can't hit. If you can fill in a spreadsheet and follow numbered steps, you can build this.
You've got this - paste the first prompt.