Purchase orders and invoice checks
Draft purchase orders from stock data and compare invoices with orders and deliveries. Buyers review exceptions and approve.
Results
- returned to the two buyers
- 16 hours a week
- of invoice lines matched to the order and the delivery without a buyer touching them
- 80%
- to prepare the weekly supplier orders, down from about 3 hours
- 45 minutes
- orders placed or invoices paid without a buyer's approval
- 0
Measured over the first three months on about 400 supplier invoices and 60 purchase orders a month.
Matched lines reach the approval queue with the three documents attached. The buyer's checking time is spent on the 1 in 5 invoices that carry a real difference.
The problem
Buyers were checking stock, preparing supplier orders and comparing invoice lines with orders and deliveries by hand.
Two buyers ran purchasing for the warehouse. Each week one of them went through stock levels and recent sales by hand, worked out what to reorder and typed the supplier orders. That took most of a morning.
Invoices were the bigger cost. Every invoice line was checked against the order and the delivery note by eye, about 400 invoices a month at around 12 minutes each. Price changes and short deliveries were caught late or missed.
Preparing an order and checking an invoice are related tasks that need different evidence. The project used stock and recent sales for the order side, and the order, the delivery and the invoice for the checking side. Buyers kept every approval.
What we built
The workflow prepares reorder suggestions and purchase orders, then flags mismatches for review.
- Prepare reorder suggestions from stock levels and recent sales.
- Draft purchase orders by supplier for buyer approval.
- Compare invoice quantities and prices with orders and deliveries.
- Flag price changes, short deliveries and unfamiliar suppliers.
How we built it
- Mapped supplier and item codes across the stock system, purchase orders, delivery notes and invoices, so the same product is recognised in all four.
- Built reorder suggestions from current stock, recent sales and each supplier's lead time, grouped into one draft order per supplier.
- Added the three-way check. Each invoice line is compared with the order line and the delivery line on quantity and price.
- Agreed the exception rules with the buyers: any price change, any short delivery, any supplier not on the approved list, and any invoice with no matching order.
- Ran it beside the manual checks for six weeks and compared every flag before switching over.
What changed
The buyer reviews prepared orders and flagged exceptions. The workflow does not place orders or pay invoices without approval.
The buyer starts the week with draft orders to review instead of a spreadsheet to build. Invoices that match on every line go to the approval queue with the evidence attached. The rest come to the buyer with the mismatch highlighted.
About 1 in 5 invoices carries a real difference, most often a price that changed after the order was placed. Those take a buyer about 10 minutes each to resolve, which is where the remaining checking time goes.
We underestimated the code mapping. Three suppliers used their own item codes on invoices, and the match rate sat at 55% until we built the translation table. After that it settled at 80%.
How the workflow fits together
What we measured and how
Each figure in the results block comes from one of these measurements.
| What we measured | How | Result |
|---|---|---|
| Buyer time on orders and invoice checks | Logged for four weeks before go-live and again in month three. | From about 21 hours a week to 5, so 16 hours returned |
| Invoice lines matched automatically | Counted in the match log as lines that agreed on quantity and price with the order and the delivery. | 80% in month three, from 55% in month one |
| Order preparation time | Timed weekly runs, from opening the stock data to sending the orders. | 45 minutes, from about 3 hours |
| Missed mismatches | A six-week parallel run in which every manual flag was compared with the system's flags. | 3 missed before the code mapping was fixed, none after |
| Approvals bypassed | Every order and payment checked for a buyer's approval record. | 0 |
Planning a similar project
These are questions to resolve with your team before implementing a similar workflow.
| Decision | What to establish |
|---|---|
| Source records | Can the same supplier and item be identified across stock, purchase orders, deliveries and invoices? Resolve those mappings before relying on a match. |
| Exception rules | Who reviews changed prices, partial deliveries and unfamiliar suppliers? Agree which differences need approval and what evidence the buyer should see. |
| Approval boundaries | Who may approve a purchase order or a payment? Keep those decisions separate from preparing a document or flagging a mismatch. |
Questions about this workflow
Does the workflow place orders or pay invoices?
No. It prepares supplier orders and checks invoice lines. Buyers review and approve. In three months no order was placed and no invoice was paid without a buyer's approval record.
What is being matched in this case?
Invoice quantities and prices are compared with the purchase order and the delivery record, line by line. Differences such as a changed price or a short delivery are flagged for the buyer with the three documents side by side.
What should a buyer measure after implementation?
Compare the time spent preparing orders and checking invoices, the number and type of exceptions, and the work needed to resolve them. Check both missed mismatches and unnecessary flags. This case measured those through a six-week parallel run against the manual checks.
Discuss your workflow.
Tell us which systems your team uses and where the work gets stuck.