The Advisory Circular AC 00-69, Best Practices for Airborne Software Development Assurance Using EUROCAE ED-12( ) and RTCA DO-178( ), initially issued in 2017, supports application of the active revisions of ED-12C/DO-178C and AC 20-115. The AC does not state FAA guidance, but rather provides information in the form of " best practices" complementary to the objectives of ED-12C/DO-178C.
- Notably, the guidance of FAA Order 8110.49 regarding "Software Change Impact Analysis" was removed in Revision A of that notice in 2017. The best practices that AC 00-69 now describes for Software Change Impact Analysis are much reduced and less prescriptive than what was removed from Order 8110.49. [1] [2]
- This AC clarifies that Data Coupling Analysis and Control Coupling Analysis are distinct activities and that both are required for satisfying objective A-7 (8) of ED-12C/DO-178C and ED-12B/DO-178B, adding that data and control coupling analyses rely upon detailed design specification of interfaces and dependencies between components.
- The AC also recommends that error handling (how the software avoids, detects, and handles runtime error) should be defined in explicit, reviewed design specifications rather than implemented ad hoc in the source code.
References
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^ Tom Ferrell (9 August 2018).
"Thread: [SystemSafety] Report on Risks of UAVs in US NAS". The System Safety Mailing List. Faculty of Technology, Universität Bielefeld. Retrieved 2020-08-27.
It's also fair to note that many of the items removed from the order have found (or are planned to find) a home in less prescriptive guidance from the FAA (e.g., FAA AC 00-69, Best Practices in Software Development).
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"8110.49A Software Approval Guidelines" (PDF). FAA Order.
FAA: 1–2. 2018-03-29. Retrieved 2020-08-27.
Explanation of Changes. FAA Order 8110.49 Chg 2, dated 4/10/17, Chapters 5 – 16 were deleted to eliminate duplication or conflict since the topics previously addressed in these chapters are now addressed in AC 20-115D, AC 00-69, or were removed.