PO Change Order Manager

The problem this kills

A buyer agrees to a price bump or a new delivery date over email. Someone updates the ERP by hand. Three weeks later the PO shows a number nobody can explain, the supplier swears they were promised something different, and finance is staring at a commitment that doesn't match the original approval.

PO changes are where clean procurement quietly falls apart. The original PO went through approval. The changes didn't. They live in inboxes, hallway conversations, and overwritten ERP fields with no history. When a change quietly pushes the order past an approval threshold, nobody catches it - because there's no system watching.

This plan kills that. Every change becomes a tracked, reasoned, approved revision - or it doesn't happen.

What you'll build

A small, secure web app for your procurement team:

• Pick an issued PO and see its current lines (quantity, price, dates).
• Draft a change - adjust quantity or price, move a delivery date, add a line, or cancel one - and write down why.
• See the delta clearly - old vs new, side by side, with the recomputed PO total and the change in committed value.
• Let the system decide if the change needs re-approval, based on your threshold and tolerance rules.
• Route it to the right approver, who signs off (or rejects with a reason).
• Commit an immutable new revision - v2, v3, v4 - never overwriting history.
• Email the updated PO to the supplier automatically once it's approved.
• Export the full change log and each revision as a clean CSV (and a PDF) for your records or to re-key into your ERP.

What's inside the Implementation Plan

The plan is a single markdown file you paste into an AI coding agent (Claude Code). It builds the whole tool with you, step by step, each step ending in a ready-to-paste prompt.

It starts by interviewing you about your business. Before writing a single line of code, the plan has the agent ask about your current change process, the systems and spreadsheets you use, the exact shape and naming of your PO data (PO number formats, line codes, SKU conventions), your real approval thresholds and price/quantity tolerances, your typical and peak change volumes, and your messy edge cases - then it reflects a short tailored spec back to you for a thumbs-up. The tool you get is shaped to your procurement reality, not a generic template.

From there it walks through: the data model with immutable revisions, the change-drafting screen with the old-vs-new delta, the threshold engine that decides on re-approval, the approval gate, the supplier email, and the CSV/PDF export - plus a "no API yet?" path so you can build the whole thing today using just a spreadsheet of your POs.

The governance it includes (this is the point)

This isn't a toy. The governance is the product:

• Login so only your team can use the tool.
• Row-level security so people only ever see their own organization's data.
• A complete audit trail - who drafted, who approved, what changed, and when.
• A hard human-in-the-loop approval gate - the system drafts and flags; a person with the right authority must approve before any revision is committed or any supplier is notified.
• Immutable revisions - history is never overwritten; every v2, v3, v4 is stored with its reason.
• Duplicate guards - keyed on PO number + revision; it warns you when two open change requests target the same line.
• Closed-PO protection - changes are blocked on cancelled or closed POs.

Who it's for

Buyers and procurement managers whose PO changes today live in email, and whose ERP shows a value nobody can explain. If you've ever had to reconstruct why a PO total moved - or wished a price bump had quietly tripped a re-approval before it shipped - this is for you. No coding background needed.

You've got this - paste the first prompt and let the agent interview you.