A single average lead time across twelve suppliers looks tidy in a slide. It also conceals the two names that miss every ocean cut-off while three others arrive early enough to inflate warehouse cover.
When we open a vendor lead-time reporting file, the first chart is almost never the portfolio average. It is a ranked slip distribution: how many days each vendor sits beyond the promise date that the buyer actually used.
What to measure instead
Agree whether the clock starts at the purchase-order confirmation, the ex-works ready notice, or the vessel departure. Then keep that definition stable for the window under review. Mixing clocks is how “analytics” become arguments.
Separate inland dwell after berth from factory performance. In Hong Kong import lanes, those two stories often travel under one late label.
A practical check before your next committee
Export the last six months of receipts for your top ten spend vendors. Plot days late without averaging them together. If two names dominate the right-hand tail, your buffer conversation belongs with them — not with the whole list.