Logistics
Planning backwards from a fixed date: the acrylic lead time chain
Lead time is not one number. It is a chain of seven steps, and the date fails at whichever link was never scheduled.
Logistics
Lead time is not one number. It is a chain of seven steps, and the date fails at whichever link was never scheduled.
When a customer asks how long an order takes, the honest answer is a chain rather than a figure. Sampling is 3 to 7 business days and production is 7 to 15, but those two numbers only describe the middle of the process. The steps on either side are where dates are lost.
| Step | Typical duration | Who controls it |
|---|---|---|
| 1. Enquiry to quotation | 1–3 business days | Us |
| 2. Drawing check and clarification | 1–3 business days | Both |
| 3. Drawing approval | 1 day to weeks | Customer |
| 4. Sampling / first article | 3–7 business days | Us |
| 5. Sample approval | 1 day to weeks | Customer |
| 6. Production | 7–15 business days | Us |
| 7. Packing, freight, customs, site delivery | 2 days to 5 weeks | Freight, customs, site |
Steps 3 and 5 are the customer steps and they are where most schedules actually slip. Step 7 is the longest and least predictable, and it is the one most often left out of a plan.
It is worth being explicit about what they mean. Sampling is 3 to 7 business days for a first article, counted from an approved drawing. Production is 7 to 15 business days for a batch, counted from sample approval or from the drawing approval if no sample is required. Business days exclude weekends and public holidays.
Take the date the part has to be on site, not the date it has to be ordered, and subtract:
For an international exhibition with a fixed opening, that chain typically comes out at four to five weeks before build-up. Anything shorter is possible for simple parts but should not be assumed for a bonded vitrine with lighting.
| Cause | Typical delay | How to avoid it |
|---|---|---|
| Drawing not approved | Days to weeks | Approve against a marked-up drawing within 48 hours; nominate one approver |
| Sample revisions | 1 to 2 weeks per round | Send the frame dimensions and a reference photo with the first order |
| Sheet grade not in stock | 5 to 10 days | Specify the grade early; ask us to confirm stock at quotation |
| Adding a finish after quoting | 2 to 5 days | Confirm the finishing scope before release |
| Freight and customs | 3 days to 3 weeks | Book the forwarder at order, not at completion |
Slack in the wrong place is wasted money and slack in the right place is insurance. The right place is freight and site delivery, not production. Compressing production to buy freight time means overtime rates and a higher defect risk; holding two weeks of freight buffer costs nothing but a slightly earlier order date.
We will give a dated production commitment at order, tell you the day we know if something is slipping, and split a shipment if part of the order is ready and the date is at risk. We will not promise a date that depends on someone else approving a drawing on a day they have not committed to.
A single flat part in stock material can sometimes be cut in 3 to 5 business days. Polished, bonded or printed parts cannot be compressed much below the sampling range, because the finishing is hand work.
Sometimes, on a batch where the constraint is machine time. It does not help when the constraint is material, drying or a customer approval, and we will say which constraint is real.
Air express is typically 5 to 10 days door to door; sea freight is 3 to 6 weeks depending on the route. Both exclude customs clearance, which varies by destination.
Yes, on a call-off agreement with a defined storage period. Holding stock decouples the customer schedule from our lead time, which is the usual arrangement for a rolling build plan.
We tell you the day we know, not the day the order ships, and we offer what is achievable: a partial shipment, an air upgrade at shared cost, or a re-sequenced batch. A missed date is a conversation, not a surprise.
We will work back through the chain and tell you where the schedule is actually tight.