Guides
Lead time ends when the stock is sellable, not when the truck arrives
Your supplier's quote stops at the dock. Your reorder math needs the span that stops when a unit can be picked and sold — and the distance between the two is a quantity error, not a rounding error.
The truck is not the finish line
A lead time is not a property of a supplier. It is a span between two events — the latency between the initiation and the completion of a process (Wikipedia). Move either endpoint and the number changes without anything in the physical world moving with it.
Most stores inherit the supplier's pair of endpoints. The supplier starts its clock when it accepts the PO and stops it when a carrier signs the goods over, because that is the interval it is accountable for. Replenishment needs a different pair: start when you issue the order, stop when a unit can be picked, allocated and sold.
Standard framing names the missing piece. Lead time decomposes into preprocessing, processing and postprocessing — and postprocessing is the time required to make a purchased item available in inventory after receipt, including quarantine and inspection (Wikipedia). The supplier's quote covers the middle. Your supplier record is supposed to hold the whole thing.
The legs nobody quotes, because they happen after the supplier is done
The tail stays invisible for an organisational reason, not a technical one. Every leg in it begins after the supplier's obligation has ended and before the ops team starts counting. It belongs to nobody's metric, so nobody reports it.
Customs entry comes first, and its duration is driven by documentation completeness and whether the shipment is selected for examination — which is why nobody quotes it as a fixed number of days (USA Customs Clearance). Then deconsolidation. Then the receiving appointment: a container that has arrived is not a container that has been unloaded, and a trailer can sit in a yard waiting for a slot. Then the dock-to-stock legs — receiving and verification, inspection and QC, labeling and data entry, putaway and the system update.
Dock-to-stock is the duration from arrival at the receiving dock to inventory being available in the warehouse system for picking and allocation (Hopstack). Its endpoints slide too, and the same way: start the clock at the receiving scan and the yard wait vanishes from the measurement; stop at physical putaway rather than system confirmation and you have called stock sellable before anything can allocate it (KPI Depot).
| Leg, in order | Inside the supplier's quoted lead time | Inside PO issued → sellable |
|---|---|---|
| PO issued, supplier accepts | Yes — the quote's own starting line | Yes |
| Production or pick-and-pack | Yes | Yes |
| Transit | Usually — to the agreed Incoterm, no further | Yes |
| Customs entry and exam | No | Yes |
| Deconsolidation | No | Yes |
| Receiving appointment / yard wait | No | Yes |
| Count and QC | No | Yes |
| Labeling and data entry | No | Yes |
| Putaway | No | Yes |
| Flipped to available in the system | No | Yes — this is the finish line |
Measure it from your own receipts, not from the quote
None of this needs new instrumentation: both timestamps already sit in your records. The date you issued the PO is on the purchase order; the date those units first became available is in your inventory history. The real span is a subtraction.
Take the last several receipts per supplier, compute the full span for each, and set the quoted figure beside them. The gap is not noise; it is the uncounted tail, itemised by arithmetic instead of settled by argument.
Three cautions, because the measurement corrupts easily. Use the date the stock went available, not the date on the delivery note — the delivery note is the supplier's endpoint, and adopting it reproduces the error you are removing. If receiving is batch-updated, a warehouse posting Friday's arrivals on Monday inflates the tail with a process artifact; fix the cadence rather than padding the field forever. And store a typical span while noting the worst case separately: safety stock absorbs variability during lead time (Wikipedia), not a lead time defined wrong.
This is merchant bookkeeping — a spreadsheet, once per supplier, once a quarter. Assisty stores the number you arrive at; it does not compute it for you.
Suppose a supplier quotes 14 days and the product sells about 12 a day. At 14 days the cover period is 168 units. Now add the tail nobody quoted: three days in customs, two waiting for a receiving slot, two to count and put away. The first unit is sellable on day 21, so the honest cover period is 252. The 84-unit difference never came from a bad forecast — velocity was right and the supplier hit its promise. It came from a field that ended at the dock. (Illustrative numbers.)
Store the whole span on the supplier, so every suggestion inherits it
reorder point = average daily usage × lead time + safety stock
A number short by a week is short by a week of units, every time anything uses it.
In Assisty that field has one home and several consumers. Suppliers are not a contact list — each carries the lead times, order cycles and minimums that decide when you reorder and how much. Set a supplier's Lead Time, Reorder Cycle, Min Stock Cover Days and order minimums and maximums once, and the buying table's suggested quantities use them automatically. A corrected span is not a per-SKU chore; it reaches every product on that supplier the moment it is saved.
Downstream, every suggestion is computed from your sales velocity, lead times and incoming stock, then rounded to your case sizes and capped at your maximum stock levels. A lead time ending at the dock understates the cover period — the top line the quantity is built from. The findings inherit the same dependency: the table surfaces items that run out before a reorder can land, ranked by money at stake — true only relative to the stored number. Shorten the number and the item that genuinely will not land in time never raises its hand.
Two consequences for setup. Lead time lives at supplier level, since the per-variant overrides are supplier SKU, cost, minimum order quantity and case quantity — so a route with a materially different tail is a separate supplier record, not a field on a product. And the fleet is auditable: the supplier list sorts by lead time, the quickest way to see which records still hold the quoted figure. Changing one is a sentence — "Change Acme Supply's lead time to 7 days" — and tomorrow's reorder suggestions use it.
| What the number has to do | What Assisty does | Where |
|---|---|---|
| Store it | Set each supplier's Lead Time, Reorder Cycle, Min Stock Cover Days and order minimums and maximums once | Suppliers |
| Use it | Every suggestion is computed from your sales velocity, lead times and incoming stock | Smart Buying Table |
| Flag against it | Surfaces items that run out before a reorder can land, ranked by money at stake | Smart Buying Table |
| Scope it | Lead time is a supplier-level rule; per-variant overrides are supplier SKU, cost, minimum order quantity and case quantity | Suppliers |
| Audit it | Sort the supplier list by name, lead time or product count | Suppliers |
| Change it | "Change Acme Supply's lead time to 7 days" — tomorrow's reorder suggestions use it | Suppliers (assistant) |
The supplier owns the middle of the span. You own both ends — and the number that decides how much to buy.