Arc Skills / Standards and development assurance
Review a standards applicability and tailoring matrix
This task checks whether a project’s standards matrix fits its actual product and approved basis. Arc Skills returns a bounded applicability review that keeps each original selection visible beside the question it raises.
Use this skill
Use Arc Skills to review this standards applicability and tailoring matrix for the named project baseline. Compare each selected edition and in/out decision with contract, certification basis and actual architecture.
Inputs:
- Controlled basis, product boundary and architecture.
- Matrix rows with editions, applicability and rationale.
- Tailoring, deviation and approval records.
Return reviewed rows with original decision, contradiction, evidence and needed authority question. Mark clauses unassessed if their controlled text is unavailable; reconcile checked and unchecked counts.What you provide and what you get
| What you have | How it is used | What you get |
|---|---|---|
| Contract/certification basis | Defines the source of project obligations | Selected-standard list |
| Product architecture | Tests in/out rationale against what is built | Applicability finding |
| Matrix and approval trail | Tests edition and tailoring decision | Corrective question |
An in-house FPGA contradicts an all-COTS exclusion
Illustrative engineering example.
A synthetic avionics matrix says DO-254 is out of scope because “all electronics are COTS.” The architecture list includes an FPGA whose logic is configured in house. No approved classification record or item-boundary rationale is attached.
| Source and original choice | Architecture evidence | Review finding | Needed decision |
|---|---|---|---|
| DO-254/ED-80: out; all COTS | FPGA F-1 programmed in house | Rationale does not fit stated architecture | Confirm approved item classification and hardware basis |
| DO-178C: in for controller software | Controller SW-1 on release list | Document-level choice is consistent | Confirm edition and software-level allocation |
| Environmental qualification basis: in | Thermal and vibration tests listed | Relevant activity named, clause coverage unassessed | Confirm agreed edition and affected units |
The review checks three supplied standard rows at document level: one contradictory rationale, two plausible selections, and zero assessed clauses. That is a scope finding, not a declaration that every DO-254 objective applies to F-1.
The hardware item classification, authority agreement and controlled standard edition are needed before a clause-level disposition. A newer published edition should not silently replace the project’s agreed basis. The matrix should preserve the original COTS claim so the decision trail remains auditable.
Test each selection against the built product
- Identify the obligation source: regulation, accepted means, contract or project policy.
- Freeze edition, amendment, item boundary and approved tailoring path.
- Compare every exclusion with architecture, supplier role and project work.
- Record reviewed scope and send unresolved applicability changes to the named authority.
Questions about this task
Does an in-house FPGA automatically make DO-254 applicable?
It makes an all-COTS rationale suspect. The approved hardware classification and project certification basis determine the formal applicability decision.
Can an online standards index establish a clause finding?
No. It identifies publications and scope; inspect the controlled edition and agreed tailoring for a requirement-level finding.
Sources and further reading
- FAA AC 20-152A: Official guidance on airborne electronic hardware development assurance.
- FAA AC 20-115D: Official guidance on airborne software assurance using DO-178C and applicable supplements.
- ECSS engineering standards index: Official catalogue for identifying the project-selected engineering standards and editions.
The official sources establish publication scope; this example makes no clause-level or certification decision.