If you buy from more than one supplier, chances are your spreadsheet still carries a single "lead time" per supplier — whatever number was quoted when you first started working together. In practice that figure is rarely what actually happens, and the spread between suppliers is far wider than an industry average would suggest.
Carrier on-time performance barely means anything as an average
Global carrier schedule reliability dropped to 56.4% in July 2026 — down 6.1 points from June and the worst monthly reading since February 2025. Vessels that do miss their window arrive an average of 6.06 days late, the highest figure since January 2024.
But the number that actually matters for your business isn't the global average — it's the spread between individual carriers. That same month, Maersk hit 73.7% on-time, while Wan Hai managed just 29.8% — a 44-point gap between the best and worst performer. If your supplier books with a lower-reliability line, the "56.4% industry average" tells you nothing useful: your real lead time depends on who your specific supplier ships with, not the market-wide number.
A quoted lead time is an assumption, not a measurement
The same problem exists one level up, with the supplier relationship itself. Whatever lead time you were quoted at onboarding is a starting assumption, not a fact. The only way to know a supplier's real lead time is to look at your own purchase-order history — how long deliveries actually took, not how long you were told they'd take.
Lead-time gap = supplier's actual average lead time − assumed lead time
A supplier running +6 days over quote isn't an outlier — given July's numbers, it's close to standard for anyone booking with the less reliable carriers. And if that supplier still feeds into your reorder-point math at the "old" lead time, you're quietly understating your own stockout risk.
The risk lead-time data doesn't catch: how much you depend on one supplier
There's a second risk that on-time percentages don't capture at all: how much of your purchase volume sits with a small number of suppliers, or in a single region. Spain's clearest recent case study is the flash flooding (DANA) that hit the Valencia region in October 2024. Per industry group Fedacova, around 200 food and agriculture companies were affected, 83% of them micro-businesses or SMEs. A follow-up study, "Resiliencia Tecnológica: Impacto y Oportunidades PostDANA," found that only 6 out of every 100 Valencian companies had an emergency protocol in place before the flooding — and among large enterprises, just 2.9% did. Company size bought no protection when the whole supply base sat in one region.
The question the analyzer answers isn't "is this supplier good?" — it's "what share of my purchase volume depends on them, and what happens the day they can't deliver?" To put a number on that, we use the same metric U.S. antitrust regulators (DOJ/FTC) use to measure market concentration — the Herfindahl-Hirschman Index (HHI) — applied here to your supplier base instead of a market:
HHI = Σ (each supplier's share of purchase volume, in %)²
Under 1,500: low concentration. 1,500–2,500: moderate. Above 2,500: high — a single failure can stop your business.
Analyze your own purchase-order history
Upload a CSV of your recent orders and the lead time you've been assuming. In seconds you'll see, per supplier, the actual average lead time, the min/max range, and the gap versus what was quoted — free, no account required. Create a free account to also unlock your supplier concentration risk (HHI) and a per-supplier reliability ranking with an improving/worsening trend.
Go to the supplier order analyzer →What to do with this
- Upload the last twelve months of purchase orders and compare each supplier's actual lead time against whatever you're currently using for reorder-point math. If the gap runs several days, update it.
- If one supplier accounts for a large share of your purchase volume, get a qualified backup in place now, even if you never end up using it — that's the difference between a bad week and a business stoppage the day they can't deliver.
- Track each supplier's trend, not just their average: one that's getting worse order over order is a growing risk even if the current average still looks fine.
Sources
- Global carrier schedule reliability and average delay, July 2026: El Estrecho Digital.
- Impact of the October 2024 Valencia flooding (DANA) on the region's food and agriculture sector (200 companies, 83% micro/SME): Ibercaja Agroinforma / Fedacova.
- Emergency-protocol adoption among Valencian companies post-DANA (6% overall, 2.9% among large enterprises): Valencia Plaza.
- Standard Herfindahl-Hirschman Index (HHI) concentration thresholds: U.S. Department of Justice, Antitrust Division.
The lead-time gap figures in the worked example are illustrative. Swap in the real numbers from your own purchase-order history using the analyzer.