A Realistic First Article Inspection Timeline
The first article date in a quote is usually the date the part comes off the machine, not the date a signed report reaches your desk. Those are different events, often a week apart, and the gap is where project schedules die. If you are planning a build around a three-week first article, the useful question is not "how long does machining take" but "which of the steps between PO and report has a queue in front of it." This is the schedule for a moderately complex part — two setups, one finish, 30 to 40 checked dimensions — with the delays that actually occur.
The twenty-one days, honestly
A simple part with one setup and no outside finish can go from PO to shipped first article in 7 to 10 days. Add a second operation, a tight true-position callout and anodizing, and three weeks is realistic. Add imported material, a five-axis feature or a coating with a plating line queue, and you are at four to five weeks before anything goes wrong.
The schedule below assumes domestic material in stock, one outside service, and a shop that starts your job when they said they would. Every day in it is a working day; add weekends and public holidays on top.
| Day | Activity | Typically owned by | Duration | What a slip here costs you |
|---|---|---|---|---|
| 1 | PO acknowledgement, drawing review, questions | Supplier | 0.5 day | Everything after shifts |
| 1 – 3 | CAM programming and setup sheet | Supplier | 2 – 3 days | Compresses prove-out, not the date |
| 2 – 3 | Material order and cutting | Supplier | 1 – 5 days | 1:1, the hard constraint |
| 4 | Fixture build or soft jaw machining | Supplier | 0.5 – 1 day | 1 – 2 days if fixture is late |
| 5 | First cut, in-process check | Supplier | 1 day | 1:1 |
| 6 – 8 | Prove-out and offset tuning | Supplier | 1 – 2 days | 1:1 |
| 9 – 10 | Deburr, wash, pre-finish inspection | Supplier | 1 day | 1:1 |
| 10 – 15 | Anodize or plating, including transit | Outside service | 5 – 7 days | 1 – 3 days on plating queue |
| 16 – 18 | CMM queue and measurement | Supplier | 2 – 3 days | 1 – 5 days at month end |
| 19 – 20 | Report writing, ballooning, review | Supplier | 1 – 2 days | Rarely late, often wrong |
| 21 | Packing, photos, dispatch | Supplier | 0.5 day | 1 day |
Programming is the step buyers assume is instant and shops treat as flexible. In practice a two-setup part takes 2 to 3 days of calendar time in a shop running several jobs, because the programmer works on it between other tasks. It rarely becomes the critical path, since material is being ordered in parallel, but it determines whether day 5 is a first cut or a second revision of the toolpath.
This is the window where questions should surface. A shop that finds an ambiguous callout on day 12 has lost a week. A shop that asks on day 1 has lost an hour. Good practice is a written DFM note with the quote, and a short confirmation call before the toolpath is finished.
Days 2 to 6: material is the constraint you cannot compress
Aluminum plate in common grades is a same-day or next-day item in Shenzhen. Stainless 17-4PH in a specific condition, titanium, PEEK or a 40 mm wall tube may be a 10 to 15 day mill order with a minimum quantity that exceeds your requirement.
If your material needs a mill certificate to EN 10204 3.1, add 1 to 3 days for the paperwork even when the bar is in stock. The metal exists; the document has to catch up.
See also: CNC Capacity Planning: Reading a Supplier's Promise Date and How to Build an Incoming Inspection Plan for Machined Parts.
Days 5 to 8: first cut and prove-out
The first cut is one day. Proving the process is one to two more. In that window the operator cuts, measures, adjusts offsets, cuts again, and confirms that the part is stable after the fixture settles. Thermal growth on a long cycle, tool deflection in a deep pocket and chip evacuation in a blind slot all reveal themselves here, and each one is a small change rather than a rewrite.
Days 9 to 15: finishing and the outside service queue
Anodizing is where schedules quietly extend. A typical Type II clear anodize runs 3 to 5 working days in a plating shop's queue, plus one day each way for transport and one day for packing. If the shop sends parts twice a week, a part that finishes on a Wednesday may not leave until the following Monday.
Days 16 to 21: CMM queue, report and review
A CMM is a single machine with a queue. At month end, when every shop is pushing to invoice, that queue is 3 to 5 days deep. On a part with 40 dimensions, the measurement program itself takes 45 to 90 minutes, and if the program has to be written from scratch, add 3 to 4 hours of programming before the first part is even mounted.
You can shorten the queue by asking two questions at quote time: how many CMMs does the shop run, and what is the current lead time for a full dimensional report? A shop with two CMMs and a dedicated inspector answers in seconds. A shop with one CMM and a shared operator will say "about a week" and mean it.
Writing the report is 4 to 8 hours for a 40-dimension part: ballooning the drawing, transcribing values, attaching material and finish certificates, and checking that every callout is answered. Review adds an hour. This is the step where the report arrives on time but incomplete — 32 of 40 dimensions, no material cert, no finish thickness — and you spend three days asking for the rest.
Send a report template with the PO. A one-page table of dimension number, nominal, tolerance, actual, and pass/fail is enough, and it removes the most common form of rework.
Where the schedule actually breaks
In practice, four causes account for most late first articles: material that was quoted as in stock but was not, a finish queue that was estimated at 3 days and ran 7, a CMM backlog at month end, and drawing questions raised after the first cut. Only one of those is machining.
Our standard first-article window is 7 to 10 days for straightforward parts, which covers programming through a dimensional report with no outside finish. Once a finish and a second operation are added, plan on three weeks and treat anything faster as a bonus. You can see how we sequence a program on the how we work page, and send a drawing through contact if you want the schedule quoted step by step.
Frequently asked questions
How long does a first article inspection take in total?
Seven to ten days for a simple one-setup part with no outside finish, and three weeks for a part with a second operation plus anodize. Most of the additional time is material lead time, finishing queue and CMM scheduling, not machining.
Can the FAI be done faster if I pay for expediting?
Sometimes, by 3 to 5 days. The compressible parts are the CMM queue and the plating queue, both of which respond to money. Material lead time and machine time are much less elastic.
Why does the report arrive a week after the parts?
Because the parts finish before the measurement and documentation do. A CMM queue of 2 to 5 days plus 4 to 8 hours of report writing sits between the last cut and the signed document.
Should the first article be fully inspected or sampled?
Fully inspected, with every drawing dimension reported and actual values shown. Sampling starts with production lots, once the process has been proven on the first article and a capability run.
Related reading
Send a drawing for a quote and DFM review.
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