On a machine build, one late part can hold up an entire assembly. The frame is welded, the drives are mounted, the panel is wired, and the build waits on a $12 sensor that was promised last week. The cost of that delay is not the sensor: it is the idle days, the rescheduled commissioning and the customer call nobody wants to make.
Late parts are rarely a surprise to the supplier. They are a surprise to you because nobody was looking at the right dates. This guide sets out a simple way to track purchase orders and late parts, the weekly routine that keeps deliveries visible, and a free Excel tracker you can start with today.
What to Track on Every Purchase Order Line
Track by line, not by order. A purchase order with eight lines can be half delivered, and a tracker that only says "PO 1043: ordered" hides the one line that matters. For each line, record:
- PO number and supplier - so you know whom to call.
- Part number and description - what is actually late.
- Quantity ordered, and later quantity received if deliveries are split.
- Date ordered - when the clock started.
- Need-by date - when the build requires it.
- Promised date - what the supplier committed to.
- Date received - filled in at the dock.
- Status - one value from a short fixed list.
- Days late - calculated, never typed.
The two dates are different on purpose. The need-by date comes from your schedule; the promised date comes from the supplier. The most useful check in the whole tracker is any line where the promised date is later than the need-by date, because that line is late before it has even shipped.
Keep Statuses Short and Honest
Statuses only help if everyone uses them the same way. A short list is enough: Draft, Sent, Ordered, Part received, Received and Cancelled. Define what each one means in a sentence, for example "Ordered means the supplier has confirmed the order and given a date", and resist adding more. If a line has a status that needs a paragraph to explain, put the paragraph in the notes column.
A Weekly Routine That Catches Late Parts
A tracker is only as good as the habit around it. A 20-minute routine, once or twice a week, does more than any amount of tooling:
- Sort by promised date. Everything due this week is at the top.
- Chase what is due in the next 5 working days. A short, specific message works best: "PO 1043, line 3, due Thursday. Can you confirm it ships today?"
- Look at what is overdue. For each line, get a new date in writing and update the promised date. A date that is not written down is not a commitment.
- Compare promised dates with need-by dates. Anything that no longer fits the schedule goes to the project manager the same day, with options: expedite, substitute, or move the build step.
- Check for partial deliveries. A delivery note that says 3 of 4 is a late line, not a received one.
Order Long-Lead Items First
Most late deliveries are decided at the moment of ordering. Sort the parts list by lead time, not by assembly, before you place the first order, and order the slowest items first. A custom-machined part with a six-week lead time should not wait behind a box of connectors that ships tomorrow. If you keep lead times in your bill of materials, this sort takes seconds; if you do not, it is the strongest reason to start.
Check Stock Before You Order, Not After
Duplicate orders are the quiet cousin of late orders. Parts you already own get ordered again because nobody checked, and the money tied up in them is not available for the parts you actually need. Check available stock against the quantity required before raising a purchase order. Our guide to stock management for assembly workshops shows how to keep that record trustworthy.
Measure On-Time Delivery by Supplier
Once the tracker has a few projects in it, it answers a question you could not answer from memory: which suppliers are actually reliable? For each supplier, count the lines delivered on or before the promised date and divide by the total lines delivered. For example, 18 of 24 lines on time is 75%.
The number is not for blaming anyone. It tells you whom to order from first when time is short, whom to give more buffer, and which supplier needs a conversation. It also makes the next supplier review a discussion about facts. Remember to measure against the promised date rather than the need-by date, since the first shows reliability and the second shows planning.
Free Excel PO Tracker
We built the routine above into a free Excel tracker. It has a row for each purchase order line with the fields listed earlier, a status drop-down, and shading that turns received lines green and late lines red. Days late is calculated for you: today minus the promised date, for any line that is not received or cancelled. A summary sheet counts open lines, received lines and late lines, and adds up the value still to be received. It has room for 300 lines and a short how-to sheet. No sign-up or email address is needed.
Download it, with a BOM template and a cost and quote worksheet, from the free templates page. The example rows are fictional so you can delete them and start with your own orders.
When the Tracker Outgrows the Spreadsheet
A spreadsheet tracker works well for one builder with a handful of active orders. It struggles when several people place orders, when the same supplier serves multiple projects, or when the tracker is a separate file from the parts list, so every order has to be typed twice and every change made twice.
In AssembleFlow, purchase orders are created from the parts list, so quantities, prices and supplier details do not have to be retyped. Exporting a purchase order marks the parts as Order Placed and records the order in the Order List, with its supplier, date, value and status. A delivery tracker per assembly holds the order placed, delivery requested and supplier commits dates, with a countdown to your factory acceptance test, and parts are ticked as received when they arrive. The Order List can also be exported as a CSV for Xero, QuickBooks, Sage or FreeAgent. You can walk through it in the product tour without an account.
Quick Checklist
- Track by order line, not by order.
- Keep need-by dates and promised dates apart.
- Use a short, fixed list of statuses.
- Calculate days late; never type it.
- Review twice a week and chase anything due within 5 working days.
- Order the longest lead times first.
- Check stock before ordering.
- Score suppliers on promised-date delivery.
Frequently Asked Questions
What should I track on each purchase order line?
PO number, supplier, part, quantity, date ordered, need-by date, promised date, date received, status and days late.
How often should I review open purchase orders?
Once or twice a week. Sort by promised date, chase anything due within five working days, and get a new date in writing for anything overdue.
Is there a free purchase order tracker?
Yes. The free PO tracker template calculates days late, colors received and late lines, and has a summary sheet. It is on the templates page.
Free tools: the Excel templates (BOM, PO tracker, cost and quote worksheet), the margin calculator and a product tour need no sign-up.