As-designed configuration is the product definition released by engineering. It reflects what the item is supposed to be, including the approved structure, parts, drawings, specifications, software or firmware definitions where applicable, and revision-controlled requirements.
As-built configuration is the recorded result for a specific serialized unit, lot, or assembly after production. It reflects what was actually manufactured, installed, inspected, tested, reworked, substituted, and released, including any approved deviations or concessions that apply to that unit.
In simple terms, as-designed is intent. As-built is evidence.
In aerospace, those two states often do not match perfectly, even in well-controlled operations. That does not automatically mean something is wrong. It may reflect normal production reality such as approved alternate parts, effectivity differences, routing changes, software loads, repair actions, dimensional results, or nonconformance dispositions. What matters is whether the difference is authorized, traceable, and correctly linked to the affected serial number or batch.
If that linkage is weak, several risks follow:
FAI and inspection evidence can become harder to defend.
Maintenance and sustainment teams may not know the exact installed configuration.
Root cause analysis becomes slower because actual build history is incomplete.
Change impact assessment is less reliable across aircraft, assemblies, or supplier lots.
Recalls, retrofit campaigns, and service bulletins become more expensive and less precise.
As-designed configuration usually includes:
released CAD and drawings
engineering bill of materials
specifications and approved revisions
planned software or firmware versions
effectivity rules and planned options
As-built configuration usually includes:
actual part and serial numbers installed
lot genealogy and material traceability
work order and routing history
inspection and test results
rework, repair, and nonconformance records
approved substitutions, deviations, or concessions
actual software or firmware loaded at release
The gap between as-designed and as-built is usually created by execution, not by design alone. Common causes include supplier substitutions, inventory shortages, manual data entry, late engineering changes, split routings across systems, offline inspection records, repair loops, and inconsistent effectivity control. In brownfield plants, the problem is often less about one bad process and more about data spread across PLM, ERP, MES, QMS, spreadsheets, and supplier portals.
That is why many organizations struggle to produce a trustworthy as-built view even when each system appears to work on its own. The issue is usually cross-system reconciliation, version governance, and evidence quality.
No. Some of it can be captured automatically, but a complete as-built record depends on how integrated and disciplined the environment is.
If machine data, operator transactions, inspection systems, QMS workflows, and serialization logic are poorly connected, the as-built record may be partially manual, delayed, or incomplete. In regulated environments, that creates obvious traceability and validation concerns. A digital thread can improve this, but only if master data, identifiers, approvals, and change control are consistently managed across systems.
Sometimes, but often not in aerospace brownfield environments.
PLM commonly remains the source for as-designed definition, while ERP, MES, QMS, and test systems contribute to as-built evidence. Trying to replace all of that with a single platform is usually harder than it looks. In long lifecycle and highly regulated programs, full replacement strategies often fail because of qualification burden, validation cost, downtime risk, integration complexity, and the need to preserve traceable historical records. Coexistence with legacy systems is the more common reality.
In practice, the better question is not which single system owns everything, but whether the organization can maintain a controlled, auditable link between design intent and actual unit history.
If you pick a serial number and ask two questions, the distinction becomes clear:
What did engineering authorize this unit to be?
What was actually installed, verified, and released on this unit?
The first answer is as-designed. The second is as-built.
In aerospace, both matter, and the operational challenge is proving the relationship between them without losing traceability through engineering changes, production deviations, and long service life.
Whether you're managing 1 site or 100, Connect 981 adapts to your environment and scales with your needs—without the complexity of traditional systems.
Whether you're managing 1 site or 100, C-981 adapts to your environment and scales with your needs—without the complexity of traditional systems.
