In many organisations, purchasing technical parts runs through an email, a phone call and a delivery note that surfaces later. That works until someone is ill, until a delivery fails to arrive and nobody knows where it is, or until the controller asks what was spent on parts this year. This article describes the process step by step. For the broader framing, see spare parts management.
Why loose emails break the process
An order that runs through email exists only in the mailbox of whoever sent it. Nobody else sees what was ordered, at what price, when it was due or whether it has arrived.
The consequences are predictable. The same parts get ordered twice. A technician waits for something nobody knows is delayed. A quotation is nowhere to be found when the invoice differs. And the question of what an asset has cost over the years can't be answered, because costs were never linked to the part or the work order.
A recorded purchasing process solves that, and it doesn't have to be heavy. What it must do: make the need visible, record the agreement and check the receipt.
The six steps
Need
It starts with a signal: available stock drops below the reorder point, or a work order calls for a part that isn't there. How to set that first signal is covered in calculating reorder point and safety stock.
Collect needs before you order. Five separate orders with the same supplier in one week cost five times the shipping and five times the admin.
Request
The request, often called an RFQ, asks for a price and a lead time. State what you need, how many, and when it has to be there. Mention the supplier's part number if you have it; that prevents most mistakes.
For larger amounts, ask several suppliers. Not only for the price, but because it reveals who gives realistic lead times.
Comparing quotations
This is where things often move too fast. The lowest price is not automatically the best choice, because a part arriving two weeks later while the machine stands still costs a multiple of the price difference.
Compare on four things: price, lead time, whether it is exactly the requested part or an alternative, and whether the supplier tends to keep their commitments. You only know that last one if you track it.
Order
The order is the moment an agreement comes into being. Record what was ordered, at what price, with what agreed delivery date and under what terms. Link the order to the work order or item it serves, so costs are traceable later.
Follow-up
Between ordering and receiving sits the phase where most goes wrong, because nobody feels ownership of it. Who watches whether the agreed date is met?
Make that explicit. A list of open orders with their promised dates, reviewed once a week, prevents most surprises. A technician waiting for a part should be able to see where it is without having to ask anyone.
Receipt
On arrival you check that it is right: the correct item, the correct quantity, undamaged. Only after that check do you book it in and is it available.
This is the moment your stock becomes reliable or doesn't. A delivery that disappears into the cupboard without being booked is a discrepancy you'll meet again months later — see cycle counting.
Who may do what
Record authority: up to what amount may someone order independently, and from what amount is a second signature required. Without that agreement you get either a bottleneck where everything waits on one person, or a situation where nobody has oversight.
Keep it simple. Two or three thresholds are enough, and make sure a stand-in is arranged in advance for absences.
Goods receipt is a control moment
Don't treat receipt as a formality. It is the last place where you can correct mistakes cheaply.
Check the quantity, and spot-check the specification: the same dimensions, the same version, the right material. A wrongly delivered seal discovered during the shutdown costs considerably more than a minute of checking at the door.
Record deviations against the order, not in a loose email. That is also your file if a claim has to be made.
Measuring what it gives you
Two figures give the most insight. Delivery reliability per supplier: what share of deliveries arrived on the agreed date? And lead time from request to receipt: how much time sits between the signal and having it available?
That second figure often surprises. Organisations who think their lead time is two weeks turn out to lose three weeks before the order even leaves the building. That is not a supplier problem but a process problem, and it is cheaper to fix.
How this works in practice, including sending requests and automatically linking supplier replies, is on the page about warehouse and spare parts.
Frequently asked questions
What is the difference between a request and an order?
A request asks for price and lead time and commits to nothing. An order is the instruction and therefore an agreement. In practice the two get mixed up, leading to discussion afterwards about what was actually agreed.
Do I always have to request several quotations?
No. For small, common items it costs more than it returns. Agree a threshold above which you request several quotations, and stick to it.
How do I link purchasing costs to a machine?
By linking the order to the work order or the item. Without that link you can never answer what maintaining an asset costs, and you need that figure when deciding whether replacement is cheaper than carrying on.
What about urgent orders outside the process?
Those are sometimes unavoidable, but register them afterwards anyway. And track how often it happens: a lot of urgency is usually a symptom of a reorder point set too low.