DO-178C: The Next Avionics Safety Standard tutorial at the SIGAda conference

2011-11-10

Andrew Coombes and Zoe Stephenson of Rapita Systems are in Denver to exhibit at and attend the ACM SIGAda Annual International Conference. Here are Andrew’s thoughts on a tutorial given by Ben Brosgol of AdaCore.

“We’ve known for some time that avionics safety standards are moving on from DO-178B (Software considerations in Airborne Systems and Equipment Certification) to DO-178C, which Ben expects to be released in 2012.

“This tutorial was a good opportunity to hear about the benefits of this change from a man with over 30 years of experience in programming languages, software development methods, safety and security, and real-time systems.

“While DO-178B has certainly resulted in software being developed in a more rigorous way for avionic systems than is currently the case for medical or automotive systems, Ben says there are still good reasons why it needed to be revised.

DO-178C allows avionic developers to accommodate “new” software technologies including object oriented programming, automatic code generators, COTS (Commercial off the shelf software) like real-time operating systems;
It incorporates supplementary material generated after DO-178B was initially released);
It corrects errors and omissions in the original standard.

“The original intention to include DO-278 (which is similar to DO-178B, but targeted at ground-based systems) has been abandoned. DO-278 will be released as DO-278A at some future time.

“During the tutorial we also looked at some of the differences between DO-178B and DO-178C, especially in the area of structural coverage – for example DO-178C will explicitly permit the use of masking MC/DC, whereas DO-178B only discusses unique case MC/DC.

“We also looked at tool qualification – this has received extensive treatment within DO-178C with the identification of Tool Qualification Levels (TQL) and qualification activities to support these.

“Interestingly, Ben observed that DO-178C (and DO-178B) do not mandate any activities that are specific to aerospace – DO-178B or DO-178C could equally be applied to automotive, nuclear, medical or any other critical industry. “Thanks to Ben for an interesting tutorial on what is still a developing story.”