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The Aerospace Safety Solution implements DO-254 compliance tracking through two integrated PowerSheets that trace the full design assurance chain — from hardware design requirements through physical characteristics to verification test results — alongside a per-objective compliance matrix that maps directly to DO-254 Tables A-1 through A-5.

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Why Hardware Needs Its Own Standard

A common misconception is that hardware verification is simpler than software verification because hardware is “deterministic.” In practice, complex programmable hardware introduces the same combinatorial state-space problems as software. A subtle timing issue in an FPGA controlling a flight control surface can be as catastrophic as a software null-pointer dereference. DO-254 exists because hardware design processes need the same discipline as software: documented requirements, controlled development, and structured verification — calibrated to the severity of what goes wrong if the hardware fails.

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Design Assurance Levels

DO-254 uses the same five-level DAL scale as DO-178C, derived from ARP 4761 failure condition classification: diagram DAL E hardware has no certification requirements. DAL A hardware requires the most comprehensive objective evidence — typically including independent verification, formal methods, and complete structural coverage. Critically, the DAL is derived from the failure condition classification assigned during the Functional Hazard Assessment; it is not manually assigned by the design team.

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The Two-PowerSheet Architecture

The Aerospace Safety Solution structures DO-254 compliance around two complementary PowerSheets rather than a single monolithic view. DO-254 Hardware Design Assurance PowerSheet provides the engineering traceability view: hardware design requirements expand to reveal their linked characteristics (SC/CC classifications, target values, tolerances) and then their verification test cases. Three progressive disclosure views control what an engineer or auditor sees:
  • Requirements Only — the audit entry point, showing only design requirements without expanding into implementation detail
  • Verification Status — collapses characteristics, surfaces test coverage and pass/fail status
  • Summary — strips descriptions to give a high-level structural overview
This three-level progressive disclosure mirrors how a certification auditor actually reviews hardware: starting with requirement completeness, then coverage, then detail. DO-254 Objectives Compliance Matrix PowerSheet maps horizontally across the five DO-254 tables (A-1 through A-5). Each objective cell independently tracks compliance status per DAL level — so an objective can be Satisfied for DAL C but still In Progress for DAL A. The five compliance states reflect real certification program realities:
StatusMeaning
Not ApplicableObjective does not apply to this configuration
Not StartedWork not yet begun
In ProgressActive but incomplete
SatisfiedObjective fully met with evidence
WaivedDER waiver obtained and documented
The Waived state is deliberately tracked — it enables DER (Designated Engineering Representative) waiver management directly within the compliance matrix rather than in a separate spreadsheet.

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The Characteristic: Hardware’s Unique Traceability Node

A concept central to DO-254 — and absent from software standards — is the Characteristic: a measurable design property with a target value and tolerance. Characteristics act as the bridge between design requirements and physical verification. Consider a power supply hardware item. A design requirement might state “output voltage shall be regulated.” The Characteristic operationalizes this: “output voltage = 28V ± 0.5V.” The test case then verifies the measurable range. This three-level chain (requirement → characteristic → test) is what makes hardware verification traceable and auditable. Characteristics carry an SC/CC classification:
  • Safety-Critical (SC) — failure of this characteristic directly contributes to a hazardous or catastrophic failure condition
  • Complexity-Critical (CC) — the characteristic involves design complexity requiring additional verification rigor
In the Flight Control Computer reference program, 47 of 63 characteristics are classified Safety-Critical — reflecting the high DAL profile of the system.

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Integration with the Broader V-Model

DO-254 design requirements sit at the design level of the four-tier ARP 4754A requirements decomposition: Customer → System → Subsystem → Design. The refines link role connects design requirements upward to system requirements, making the DO-254 design level a natural downstream node in the full V-model traceability chain. DO-254 hardware design requirements also appear in the cross-standard Whole RTM Sheet alongside software (DO-178C) requirements — enabling program managers to view the full requirements landscape without switching between tool contexts.
DO-326A security requirements for hardware are handled through a separate security decomposition and verification chain — they are not part of the DO-254 functional design assurance flow. The two standards address orthogonal concerns: DO-254 addresses safety function correctness; DO-326A addresses resistance to intentional unauthorized interference.

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What the Compliance Matrix Is Not

A common misconception: the objectives compliance matrix is not a checklist of process activities. It is a claim record — each cell represents a claim that a specific DO-254 objective is satisfied for a specific DAL level, backed by evidence on file. The evidence types (Document, Test Result, Analysis, Review Record, Inspection, Demonstration) correspond to the actual artifact categories the FAA expects to find in a Hardware Accomplishment Summary.
Procedural steps for uploading evidence artifacts, completing objective cells, and managing DER waivers should be verified in the live application. Only the configuration structure and data model are documented here.
For practical guidance on building the DO-254 traceability chain, see the V-Model Development Process tutorial and the Design Assurance Level (DAL) Classification concept page.
Code: .polarion/nextedy/sheet-configurations/DO-254 Hardware Design Assurance.yaml (0.78) · .polarion/tracker/fields/dal-enum.xml (0.65) · .polarion/nextedy/sheet-configurations/DO-254 Objectives Compliance Matrix.yaml (0.64) · .polarion/tracker/fields/complianceObjective-standard-enum.xml, complianceObjective-status-enum.xml, complianceRequirement-complianceStatus-enum.xml, complianceRequirement-evidenceType-enum.xml (0.53) · .polarion/nextedy/sheet-configurations/DO-326A Security Requirements Traceability.yaml (0.51) · datasets/sol-aero-ui-walkthrough/summary.md, navigation.md, dashboards/home-dashboard.md, dashboards/role-dashboards.md, dashboards/standards-compliance.md, risksheet-views/risksheet-views.md, work-item-types/data-model.md (0.49) · .polarion/nextedy/models/rtm.yaml (0.48) · .polarion/nextedy/sheet-configurations/ARP 4754A System Development Assurance.yaml (0.45) · .polarion/tracker/fields/securityThreat-attackSurface-enum.xml, securityThreat-likelihood-enum.xml, securityThreat-impact-enum.xml, securityThreat-sal-enum.xml (0.43) · .polarion/tracker/fields/securityThreat-threatCategory-enum.xml (0.43)