For a manufacturing or assembly business, purchase orders are a record of procurement commitments. Good purchase order management connects parts, suppliers, quantities, prices and delivery dates; poor records create follow-up work when deliveries or prices change.
This guide covers the complete purchase order lifecycle — from the initial quote request to final delivery — in a small manufacturing business.
The Purchase Order Lifecycle
In a manufacturing context, the procurement process typically follows these stages:
1. Identify Requirements
This starts with your Bill of Materials. Once you know what parts you need (and how many), adjusted for available stock and minimum order quantities, you have your procurement requirements.
2. Send Quote Requests
For new suppliers, new components, or components where your price data is out of date, send a formal quote request (RFQ) before committing to an order. A good RFQ includes your part number, description, required quantity, and required delivery date.
Best practice: reference your RFQ with a systematic number (e.g. PROJECT-ENQ-001) so you can easily match incoming quotes to outgoing requests.
3. Evaluate Quotes and Raise Purchase Orders
Once you have prices, raise a formal purchase order. A professional PO should include:
- Your PO number (unique, systematic reference)
- Supplier details (name, address, contact)
- Your company details and delivery address
- Line items: your part number, supplier part number, description, quantity, unit price, total price
- Required delivery date
- Payment terms
- Any special delivery or packing instructions
Including the supplier's own part number on the PO helps suppliers match the order to their catalog. Suppliers pick parts from their own system — your internal reference means nothing to their warehouse.
4. Confirm the Order
Always get written confirmation from the supplier, including their confirmation of the delivery date. A PO sent but not confirmed is a risk — you don't know if the supplier has received it, accepted the price, or can meet your date.
5. Track Delivery Against Required Date
The gap between "supplier commits to deliver on X" and "part actually needed on Y" is the delivery margin. If X is later than Y, record the issue and review the available options.
Proactive delivery tracking means reviewing open purchase orders weekly (or daily for critical path items) and chasing suppliers before delivery dates pass.
6. Receive and Check Goods
When parts arrive, check them against the purchase order: correct part number, correct quantity, undamaged condition. Discrepancies should be raised with the supplier immediately — the longer you wait, the harder it is to resolve.
7. Update Your BOM and Stock
Once goods are received and checked, update your parts list to show received status and update your stock levels. This closes the procurement loop and gives you an accurate picture of project progress.
Common Purchase Order Management Problems
No Central PO Register
If purchase orders exist only as PDF files in email folders, it's difficult to get a clear picture of what's been ordered, what's outstanding, and what's been received. A central PO register — even a shared spreadsheet — gives the team a shared list. A purpose-built tool can connect those records in one workflow.
Ordering Without Checking Stock
Ordering parts that are already in stock is expensive and embarrassing. Always check stock before raising a PO — and make sure your stock records are accurate.
Missing Supplier References
Sending a PO with only your internal part number is a common cause of wrong deliveries. Always include the supplier's own catalog or part reference.
No Delivery Date on the PO
If you don't specify a required delivery date, you can't hold the supplier accountable for a late delivery. Every PO should include a specific required delivery date.
Not Following Up on Open Orders
Suppliers are busy. If you don't chase, you're not on their priority list. A systematic approach to following up open orders — especially for long lead time items — keeps the status of each order visible.
How Software Changes the Picture
Purpose-built procurement management software addresses all of these problems by connecting your BOM, stock levels, quote requests, and purchase orders in a single system:
- POs can be generated directly from the BOM, with the selected part data carried into the document
- Stock is automatically deducted before calculating order quantities
- Supplier references are stored and auto-populated on every PO
- Delivery tracking highlights overdue items automatically
- Every PO is logged and searchable
AssembleFlow provides all of this in a tool designed specifically for small manufacturing and assembly businesses. Try it free for 14 days.
Frequently Asked Questions
What should a purchase order include?
The PO number and date, supplier details, part numbers and descriptions, quantities, agreed prices and discounts, delivery date and address, payment terms, and any shipping or tax.
What is the difference between a quote request and a purchase order?
A quote request (RFQ) asks a supplier for a price and lead time. A purchase order is your commitment to buy at the agreed price and terms.
How do I stop purchase orders from getting lost?
Number every order, log it in one list with its supplier, value and status, and track each line until the goods are received.
Free tools: the Excel templates (BOM, PO tracker, cost and quote worksheet), the margin calculator and a product tour need no sign-up.