Ask a plant manager why so much spend goes outside contracted suppliers and you’ll usually hear about the system. In my experience, roughly seven times out of ten, the cause is a single approval threshold somebody set in 2018 and nobody has revisited since.
The $500 threshold that created 4,000 tiny purchase orders
A 400-person equipment manufacturer, about $60 million of annual spend, was drowning. Their buyers were issuing close to 4,000 purchase orders a year under $500 each. Average value: $187.
Every one of those needed a manager’s signature. The managers, sensibly, stopped reading them. So the approval existed on paper and did nothing except add two days of delay — while 62% of total spend went to suppliers with no contract and no negotiated price.
That’s the trap. Tight controls on small purchases, loose reality on big ones. The paperwork grows and the leverage disappears.
Three rules that cut off-contract buying by two-thirds
- Raise the approval threshold to $2,500 for anything from an approved supplier on a contract. Below that, buyers just buy. Admin cost per PO is typically $60 to $90 — you were spending $80 to control $187.
- Require a reason code for any purchase outside contract, chosen from four options: urgent breakdown, contract supplier out of stock, one-off specification, customer-mandated brand. Anything else gets rejected at entry, not three weeks later.
- Publish a monthly list of the top 20 off-contract suppliers by spend. Not as a punishment — as a buying opportunity. Four of them became contracted suppliers within a quarter, worth about $2.1 million of spend.
What surprised everyone
The buyers weren’t the problem. Once the reason codes existed, the biggest source of off-contract spend turned out to be maintenance, ordering parts at 6 a.m. from whoever would answer the phone. The fix wasn’t discipline — it was a stocked critical-spares cabinet with a simple reorder point.
This is the kind of thing a good ERP Consulting review surfaces in the first two weeks, because it isn’t hidden in the software. It’s visible in the purchase history the moment you sort by supplier and value.
Cash impact over the following year: payment terms on the newly contracted categories went from 30 days to 45, freeing roughly $480,000 of working capital. All of it from rules, not from a new module.
Start with a sort, not a meeting
Export every purchase order from the last 12 months. Sort by supplier. Then sort again by value, smallest first. Count how many POs sit under your approval threshold and what they cost you to process.
That one spreadsheet usually makes the case better than any presentation. Bring it to your next operations review and ask one question: what would we do with two extra days and $80 per order?