What it is
A first article inspection, usually shortened to FAI, is a full check of one part from the first production run against every requirement on the drawing. Not a sample of dimensions: all of them, plus the material, the processes and any tests the drawing calls for.
The point is to prove the method, not just the part. If the first part off a settled process meets the drawing in every respect, you have evidence that your routing, tooling, programs and suppliers can make the part properly.
In UK aerospace and defence supply chains the usual reference is AS9102, published here as BS EN 9102. AS9100 itself (BS EN 9100 in the UK) asks for the first production run to be verified and notes that this can be called a first article inspection. Whether AS9102 applies to a particular job is decided by your customer and their purchase order, so that is where to look first.
What the report holds
An AS9102-style report has three parts:
- Part number accountability. What the part is, its drawing issue, and any sub-assemblies or detail parts with their own FAIs.
- Product accountability. The materials used, with their certs, and every special process, with the approved supplier who did it and their cert.
- Characteristic accountability. Every dimension, note and requirement on the drawing, numbered, with the limit, the measured result and what it was measured with.
The third part is why drawings get "ballooned": each characteristic is given a numbered bubble so that the report and the drawing can be read side by side.
When you have to do it again
A first article is not once and for ever. A new one, or a partial one covering what changed, is normally expected when:
- the drawing changes in a way that affects fit, form or function
- the manufacturing method changes: a different machine, program, tooling or sequence
- the work moves to a different site or a different supplier
- a process that cannot be checked afterwards changes, such as heat treatment or plating
- production has lapsed for a long period, commonly two years unless your customer says otherwise, and then often only for the characteristics the gap could have affected
- something has happened that casts doubt on the earlier one
A partial FAI covers only the characteristics affected by the change, and refers back to the original for the rest.
Where it goes wrong
Most FAI pain is not measurement. It is paperwork arriving late:
- the material cert is in an inbox, not with the job
- the plating supplier's cert reference was never written down
- nobody is sure which drawing issue the first part was actually made to
- the report is started the day before despatch, when the part has already been packed
Each of these is a record that should have been captured when the work was done.
Making it routine
The shops that find FAI easy treat it as part of the job, not an event at the end:
- Balloon the drawing at the quote or planning stage, so the characteristics exist before the part does.
- Tie them to the drawing issue, so a new issue prompts the question of what needs re-verifying.
- Collect certs as the material and processes arrive, against the batch and the operation they belong to.
- Hold despatch until the first article has passed, so a missing report is caught by the system and not by the customer.
Done this way the report is mostly assembled from records you already have. The measuring still takes as long as it takes. The searching does not.