How should unchanged characteristics be handled in a partial FAI?

Unchanged characteristics in a partial FAI are usually handled by documented reference to the prior accepted FAI, not by automatically remeasuring every feature. The important point is not that the characteristic is unchanged on paper; it is that the organization can show, with traceability, that the design change, process change, source change, tooling change, material change, or other trigger did not affect that characteristic.

A partial FAI should be scoped from a change impact assessment. Characteristics affected by the change should be ballooned, inspected, and recorded in the partial FAI package. Characteristics not affected may normally be carried forward by reference to the original or previous accepted FAI, provided the previous evidence is still valid for the current part number, drawing revision, configuration, and manufacturing method.

Do not just omit them without explanation

For unchanged characteristics, the package should make the logic visible. Common approaches include:

• listing only the affected characteristics and referencing the prior FAI for all unaffected characteristics;
• including an impact matrix that identifies affected and unaffected characteristics;
• marking unaffected characteristics as “not affected,” “previously accepted,” or similar controlled wording;
• referencing the previous FAI report number, part revision, drawing revision, ballooned drawing, and approval status.

The exact format depends on the customer, internal procedure, AS9102 interpretation, and any portal or supplier quality requirements. Some customers expect all characteristics to remain visible in the record, even if only a subset is reverified. Others accept a narrower partial FAI if the rationale and references are clear.

What must be checked before carrying characteristics forward

Carry-forward treatment is weak if the underlying configuration is not controlled. Before relying on prior FAI evidence, confirm that:

• the previous FAI was accepted and is retrievable;
• the part number, drawing revision, specification revision, and applicable model-based definition are correctly linked;
• the characteristic was not affected by the change or by related process changes;
• manufacturing source, tooling, CNC program, material, special process, or inspection method changes have been reviewed for indirect impact;
• customer-specific FAI requirements do not require broader reinspection;
• the partial FAI record can show who made the determination and under what change control authority.

The main failure mode is treating “unchanged on the drawing” as the same as “unaffected in production.” That is not always true. A routing change, alternate machine, new fixture, supplier move, heat treat source change, or inspection method change can affect characteristics that were not revised on the drawing.

How this works in real systems

In brownfield environments, the evidence may be split across PLM, MES, ERP, QMS, inspection software, supplier portals, and document repositories. That is common, but it increases the risk of broken traceability. The partial FAI should identify the controlling revision and the authoritative prior FAI record, not rely on tribal knowledge or file names in shared folders.

Digital FAI tools can help by linking characteristics, ballooned drawings, prior FAI records, change notices, and inspection results. They do not remove the need for engineering and quality judgment. If master data, revision control, or system integrations are unreliable, the tool may only make an incorrect carry-forward decision easier to repeat.

Practical rule

Unchanged characteristics do not need to be revalidated solely because a partial FAI is being performed, unless the change impact, customer requirement, or internal procedure requires it. They do need to be accounted for. A defensible partial FAI shows what changed, what was inspected, what was carried forward, why that was acceptable, and where the prior objective evidence resides.