FAT in 14 points: the factory acceptance checklist
FAT (Factory Acceptance Test) is the only moment defects get fixed for free, while the machine is still at the factory. Our working 14-point checklist inside.
Context: our engineer in Shenzhen runs acceptance on every batch before shipment. A machine takes forty minutes to two hours depending on class. The protocol with photos and video reaches the client while the batch is still on the floor.
Acceptance happens on the factory's premises: it needs a test track, a load-test bench and access to the parts warehouse. The date goes into the contract together with a penalty for “batch not ready on the agreed date” — without that line, FAT has a habit of sliding until shipping day, when there is nothing left to check and no time to check it.
Serials vs the contract
Nameplate numbers must equal the contract annex. Batch substitution is ruled out here.
Completeness vs packing list
Stations, remotes, cables, fasteners — checked before the box closes.
Firmware versions
Pinned and identical across the batch. “It will auto-update later” is not an answer.
Power-on and self-test
Cold start, clean diagnostics, empty error log.
Navigation on the test track
Aisles, turns, stopping in front of an obstacle.
Sensors and e-stops
Every sensor is hand-blocked; the emergency stop is physically pressed.
Load test
Rated weight on trays or gripper, motion under load, incline per spec.
Battery cycle
Charge-discharge with measurement: capacity and time against the datasheet.
Dock approach
Automatic docking ×3 in a row, with no helping hand.
Noise and vibration
Measured in motion plus a subjective check: rattle is heard before it is seen.
Cosmetics and panel gaps
Panels, seams, scratches. The machine ships to a client, not “to testing”.
Marking and battery papers
UN labels, Class 9, the UN38.3/MSDS set matches the cells.
Packing and bracing
Export crate, moisture protection, fixation. Checked before the seal.
Photo and video of every SN
Each machine passes key tests with its serial in frame. That is the protocol.
Video of every machine with its serial number in frame is not paranoia. It is the only language all sides of a future dispute understand.
Part 02
Why FAT, not incoming inspection at home
The objection we hear most: “we'll check it when it arrives”. The arithmetic disagrees. A machine that has cleared customs is legally imported: returning it to the factory means re-export — a new declaration, lithium batteries shipped back as dangerous goods, 6–10 weeks and hundreds of dollars per unit. All while you pay for storage and the project stands still.
The same defect caught at FAT is turned around with the factory's own resources: their shift, their parts warehouse, their shipping plan. A board swap takes hours, a panel respray a day, a full machine replacement a week. The cost asymmetry is so crude that FAT pays for itself even if it catches a defect in one batch out of ten. Our statistics say it catches more.
Part 03
What acceptance finds most often
| Finding | Frequency · per 100 machines | Fix at the factory | If caught after delivery |
|---|---|---|---|
| Mismatched firmware across the batch | 11 | 30 minutes | weeks of remote debugging |
| Cosmetics: scratches, panel gaps | 9 | a day | a “that was the carrier” dispute |
| Missing stations and cables | 6 | added to the crate | air-freight reorder, $300+ and a month |
| Battery capacity below datasheet | 4 | cell replacement | a six-month warranty dispute |
| Battery papers for the wrong cell | 3 | a day to reissue | cargo stuck at the port |
Frequencies rounded. “After delivery” outcomes are real cases from before FAT became mandatory in our pipeline.
What FAT costs and who pays
In our deliveries FAT is not an option but a stage of the process: a staff engineer runs it, and the cost dissolves into the project budget. If you buy direct, third-party inspection in Shenzhen or Suzhou costs $250–500 per working day — on a five-machine batch that is 1–2% of the budget. Treat it as an insurance premium: it buys the most expensive surprises out of your future.
If the supplier refuses FAT
The refusal comes in three flavours: “we have our own QC, don't you trust us?”, “inspection will delay the shipment”, and “fine, but for a fee comparable to the machine”. All three mean the same thing: between you and the factory sits a link that has no interest in showing the workshop — or there is no workshop at all. A manufacturer confident in its line welcomes inspection: for them it is free proof of quality. The reaction to a FAT request is as diagnostic as a video call from the floor.
Takeaway
Who signs and what happens next
The protocol is signed by our engineer and the factory's representative; the client receives it before shipment, with the right to stop the batch. Any defect found is turned around on the spot — over a year, that is cheaper than any “we'll sort it under warranty” through customs. Hold every supplier to this checklist, including us.
FAT is one stage of the deal's mechanics
The buyer's guide covers FAT as its own chapter, with examples of what acceptance actually catches. The process page shows where this stage sits between request and launch.
Want to map this onto your site?
The two-minute audit suggests the right format — catalog, package or custom project. Or write to us directly: the conversation starts with your numbers, not a slide deck.