AC 00-69
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.
- This AC clarifies that Data Coupling Analysis and Control Coupling Analysis are distinct activities and that both are required for satisfying objective A-7 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 should be defined in explicit, reviewed design specifications rather than implemented ad hoc in the source code.