Before moving to series production of a CNC part, the question to be answered is simple: "Can this supplier produce this part to this drawing?" First article inspection (FAI; German EMPB – Erstmusterprüfbericht; ISIR – Initial Sample Inspection Report) answers this question with evidence. When sourcing from abroad, FAI is the first and most important step of quality assurance; it catches most of the problems that would otherwise emerge later, before series production begins.
What FAI Is – and What It Is Not
FAI is the complete verification of one or more parts taken from the first production batch against all dimensional, tolerance, surface, material and process requirements on the technical drawing, and the documentation of the results in a standard report. In aerospace its format is defined by the AS9102 standard; in automotive it corresponds to the "dimensional results" and "material test results" elements of PPAP; in general machine building it follows the customer's template.
FAI is product evidence, not process evidence: it shows that the part is correct, not that the process will remain correct across 10,000 parts. Process evidence requires PPAP, a control plan and a Cpk study.
When Is FAI Required?
- At the first production of a new part.
- On a design change (new drawing revision) — a "delta FAI" can be carried out for the affected characteristics only.
- When there is a change in the production process, machine, fixture, material supplier or sub-supplier (coating, heat treatment).
- When the production location changes (a move to a new supplier requires a full FAI).
- After a long production gap (2 years under AS9102; many customers define their own period).
The Process: Step by Step
1. Clarifying the requirements (RFQ/order stage)
The scope of the FAI is defined in writing in the order: how many parts will be measured (typically 1–5), which report format will be used (AS9102 Forms 1-2-3, VDA EMPB, customer template), which documents will be attached (material certificate, coating report, hardness), whether the parts will be sent to the customer. You can find ready-made wording for this in our RFQ guide.
2. Ballooned drawing
Every dimension, tolerance, surface symbol, thread, geometric tolerance and note on the drawing is numbered. These numbers correspond to the lines in the report; no characteristic is skipped. Ballooning ensures that both the manufacturer and the customer are talking about the same list.
3. Sample production — under series conditions
The sample must be produced with the machine, fixture, tooling and program that will be used in series production. A sample produced on a prototype machine with manual adjustment is not evidence of the series process. At Tornelle, samples are produced in the same set-up as the first parts of the series work order.
4. Full measurement
For each balloon number the nominal, tolerance, measured value, measuring instrument used and result (conforming/non-conforming) are recorded. Tight-tolerance and geometric characteristics are measured with a CMM, surface roughness with a profilometer, threads with gauges. Our article on ISO 2768 general tolerances helps with interpreting the report; dimensions without a stated tolerance on the drawing are also evaluated in the report against the general tolerance class.
5. Material and process evidence
The EN 10204 3.1 material certificate, heat treatment and coating reports, hardness measurement and, if required, functional test results are attached to the report. The heat number is matched to the sample batch.
6. Report and submission
The ballooned drawing, measurement table, certificates and, if there is a non-conformance, a deviation request are sent to the customer in a single file; if requested, the sample parts are also shipped physically.
7. Customer approval and series production
The customer reviews the report, verifies it with its own measurements if necessary and gives written approval. The approved sample is kept as the "master sample". Series production starts after this approval; starting series production before approval puts the whole batch at risk in the event of rejection.
If a Non-Conformance Occurs
If a dimension is out of tolerance in the FAI, there are two routes: the part is corrected and re-measured, or, if the function is not affected, written deviation approval is requested from the customer. Experienced manufacturers report characteristics they consider unmachinable or contradictory before the FAI, at the quotation stage; this is the cheapest moment for a correction.
Difference Between FAI and PPAP
| FAI / ISIR | PPAP | |
|---|---|---|
| What it proves | Part conforms to the drawing | Process can produce conforming parts consistently |
| Content | Full measurement + material/process documents | FAI + PFMEA, control plan, Cpk, MSA, PSW |
| Sector | General machinery, aerospace (AS9102), medical | Automotive (AIAG), VDA 2 in Germany |
| Preparation time | 2–5 days after sample | 1–3 weeks after sample |
Cost and Time
FAI consists of the sample production cost (set-up + parts) and the measurement/report labour; it typically requires 1–3 additional days. This cost is shown in the quote as a separate item from the series price or included in the first batch price. Skipping FAI when sourcing from abroad means accepting the risk of rejection of the first series batch and a 2–3-week shipping loop; that is why it is almost always worth doing. For its effect on the price, see our article on the 12 factors.
Frequently Asked Questions
How many parts are measured for FAI?
Usually 1–5 parts; the customer defines it. In aerospace AS9102 requires a single part; in automotive 3–5 parts are common for PPAP dimensional results.
Should the sample parts be sent to the customer?
Yes, if the customer requests it; in many cases the report and photos are sufficient, and the parts are shipped together with the first series batch.
In which language is the FAI report prepared?
English is standard; a German EMPB template can be used for German customers.
Is a full FAI required on a drawing revision?
A "delta FAI" for the changed characteristics only is sufficient; this must be agreed with the customer in advance.
Conclusion
First article approval is the lowest-cost insurance in overseas CNC sourcing: it proves the part's conformity to the drawing before series production starts and ensures both sides share the same reference. At Tornelle, FAI with a ballooned drawing and a full inspection report is offered as standard. Send your technical drawings and your FAI expectations via our quote form and receive a quote showing the sample and series prices separately.
