Certification Liaison and SOI Reviews
SOISection 08: Software Certification (DO-178C)
Definition
Certification liaison is the ongoing communication between the applicant and the certification authority throughout the software lifecycle. Stages of Involvement (SOIs) are structured review points at which the certification authority evaluates the software development and verification progress. The FAA defines four SOIs for software: SOI #1 (Planning Review) — reviews the PSAC, plans, and standards before significant development begins; SOI #2 (Development Review) — reviews requirements, design, and initial development outputs; SOI #3 (Verification Review) — reviews verification results, including test results, coverage analysis, and traceability; SOI #4 (Final Review) — reviews the Software Accomplishment Summary, open problem reports, and the complete lifecycle data package. SOIs may also include audits of the development and verification environment.
Where This Shows Up
SOI reviews are the formal mechanism by which the certification authority exercises oversight of the software development process. Early engagement (SOI #1) allows the authority to identify issues with the certification approach before significant investment is made. Mid-process reviews (SOI #2, #3) provide checkpoints for course correction. The final review (SOI #4) is the authority's assessment of the complete software certification package. The number and timing of SOIs may vary based on the certification program and the authority's risk assessment.
Primary Sources
Defines the SOI process and the FAA's expectations at each stage of involvement for software certification.
Addresses the certification liaison process and the applicant's responsibilities for communicating with the certification authority.
Artifacts Produced
Document recording the findings, observations, and action items from a Stage of Involvement review.
Across Jurisdictions
FAA Order 8110.49
FAA uses a four-SOI model (SOI #1 through #4) as defined in Order 8110.49. The ACO software specialist or designee conducts the SOI reviews.
EASA follows a similar staged review process, although the terminology and specific procedures may differ. The DOA's CVEs typically perform the equivalent of SOI reviews internally, with EASA providing oversight of the DOA process.
In the EASA DOA system, the staged review function is often performed by the DOA itself under its Design Assurance System, with EASA audit of the DOA's process rather than direct SOI reviews.
Related Terms
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