In a digital FAIR, key characteristics are identified and tracked by combining controlled definition at the source (drawing/PLM), structured ballooning, and traceable inspection data capture. The details vary by software and plant maturity, but the core pattern is consistent.
1. Identifying key characteristics
Key characteristics are typically flagged before or during FAIR creation using one or more of these approaches:
- From the drawing/PLM model: The engineering authority defines which dimensions or notes are key (e.g. via drawing symbols, layer conventions, GD&T feature flags, or PLM attributes). A digital FAIR tool then imports these and maps them into FAIR characteristics.
- During digital ballooning: While ballooning the drawing, the planner or quality engineer assigns a status (e.g. key, critical, major, minor) on each ballooned characteristic using standard codes or checkboxes.
- From routing / control plan: Some sites maintain key characteristics in control plans or routers. The FAIR system links the plan to the part and auto-marks matching FAIR characteristics as key.
- Manual override with governance: Where legacy drawings are inconsistent, users can manually mark key characteristics, usually restricted to specific roles and tracked via audit trail.
The accuracy of key characteristic identification depends on drawing standards, PLM configuration, and how disciplined planners are in maintaining those flags. Many plants run hybrid processes while they improve data quality.
2. Structuring key characteristics inside the digital FAIR
Once identified, key characteristics are represented explicitly in the FAIR record, typically as:
- Dedicated fields/flags: Each characteristic line item has a boolean or categorical field (e.g. KC = Yes/No, severity class, characteristic type).
- Standardized codes: Drop-down values aligned with internal procedures or AS9102 guidance (e.g. safety-critical, flight-critical, functional key, process control).
- Linkage to requirement source: References back to drawing balloon ID, feature ID, specification, or PLM requirement ID so that the KC can be traced through design changes.
- Association to process step or operation: The key characteristic is tied to specific machining, assembly, or inspection operations in the routing, which enables downstream tracking in MES or digital travelers.
For regulated environments, the configuration of these fields usually goes through change control and validation to ensure consistent, repeatable use across programs and suppliers.
3. Tracking measurement and results for key characteristics
Tracking in a digital FAIR is primarily about how measured values and dispositions for key characteristics are captured and kept traceable:
- Structured data entry: For each key characteristic, inspectors enter actual values, tools used, and results (pass/fail) into defined fields, not free text.
- Direct gage/CMM integration (where available): Measurement systems can push data into the FAIR record using mapping rules that align feature IDs to FAIR characteristics. This reduces transcription error but requires careful interface validation.
- Evidence attachments: For high-risk KCs, scanned CMM reports, capability studies, or photos are attached and linked to the specific FAIR characteristic line.
- Disposition linkage: If a key characteristic is out of tolerance, the FAIR record is linked to NCR/MRB workflows so there is end-to-end traceability from KC to nonconformance and disposition.
The robustness of tracking is constrained by metrology integration, data mapping quality, and how well inspectors are trained to use the digital system.
4. Maintaining visibility across lots, revisions, and suppliers
Digital FAIRs can provide ongoing visibility for key characteristics across parts and time, but only if the data model is set up correctly:
- Revision-aware records: The same key characteristic can be traced across drawing revisions using persistent IDs or PLM requirement IDs, with the FAIR clearly tied to a specific revision.
- Lot/serial traceability: Each FAIR instance links the key characteristic to lot numbers and/or serial numbers, enabling trend analysis and targeted containment.
- Supplier vs in-house views: For supplier FAIRs, key characteristic information may be imported via portals or standardized templates. Misaligned numbering or ballooning schemes between supplier and OEM are common failure modes and need explicit governance.
- Analytics and monitoring: Over time, key characteristics can be monitored for defect rate, rework, and capability, but this requires consistent coding and clean master data across programs.
In many brownfield environments, this level of visibility is achieved gradually, starting with a limited set of programs or suppliers and then expanded once processes stabilize.
5. Integration with PLM, MES, ERP, and QMS
Key characteristic tracking does not live only inside the FAIR tool in most plants. Coexistence with legacy systems is the norm:
- PLM/engineering source of truth: Design intent and KC identification usually originate in PLM or drawing systems. Without stable PLM attributes or drawing conventions, digital FAIRs often rely on manual KC marking, which is less scalable.
- MES / digital travelers: Key characteristics can be embedded in digital travelers so that in-process inspections focus on them. The FAIR then consumes these results or references them, avoiding double data entry.
- ERP linkages: Part numbers, revs, and lot information must align. Mismatches lead to KCs being tracked against the wrong configuration or order.
- QMS / NCR systems: When a key characteristic fails, the QMS handles the NCR, MRB, CAPA. The FAIR system should reference these records for traceability, not attempt to replace QMS functionality.
Full replacement of PLM, MES, or QMS with a FAIR tool is rarely realistic in regulated aerospace environments due to validation burden, downtime risk, and integration complexity. Digital FAIRs usually sit alongside existing systems and exchange key characteristic data via governed interfaces.
6. Governance, validation, and common failure modes
Because key characteristics are often safety- or performance-critical, their digital handling requires explicit controls:
- Governance: Clear ownership of KC definition (engineering), implementation (manufacturing/quality), and maintenance (data/admin). Role-based permissions to add, change, or remove KC flags.
- Validation: For aerospace and similar contexts, interfaces that import KCs from PLM or metrology systems and the rules that map them to FAIR records should be documented, tested, and periodically reverified.
- Change control: When a drawing or model changes, a controlled process should ensure that KC flags, ballooning, and FAIR templates are updated consistently and that obsolete KCs are not reused incorrectly.
Common failure modes include:
- Key characteristics not consistently flagged on drawings or in PLM, leading to gaps in the FAIR.
- Manual renumbering or re-ballooning that breaks links between measurements and KC definitions.
- Suppliers using different numbering schemes, making OEM analytics on key characteristics unreliable.
- Attempting to centralize everything in the FAIR tool without aligning PLM, MES, and QMS, resulting in conflicting sources of truth.
7. Practical implementation steps
For plants moving from paper to digital FAIRs in a brownfield environment, a pragmatic approach is:
- Standardize how KCs are indicated on drawings and/or in PLM for new or revised parts.
- Configure the digital FAIR system with explicit KC fields, codes, and audit trails.
- Pilot digital ballooning on a constrained set of parts, validating KC import and tracking against existing paper FAIRs.
- Integrate with metrology and MES only where interfaces can be reliably mapped and supported, rather than trying to cover all equipment immediately.
- Continuously review defects and NCRs on KCs to improve both the digital configuration and the underlying process.
The result, when done incrementally and with proper governance, is a digital FAIR process where key characteristics are reliably identified, measured, and traceable without disrupting existing qualified systems.
