Progress Report on Some Proposed Upgrades to the Conceptual Underpinnings of DO-178B/ED-12B

RTCA SC-205/EUROCAE WG-71 was established in late 2005 to provide the third major update to DO178/ED12, SOFTWARE CONSIDERATIONS IN AIRBORNE SYSTEMS AND EQUIPMENT CERTIFICATION, from DO-178B/ED- 12B to DO-178C/ED-12C. According to its Terms of Reference (TOR) [1], one of its key objectives is to "address emerging software trends and technologies." Over the course of the last several years of work, it has become increasingly apparent to some of us in SC-205/WG-71 that ensuring consistency among an already diverse and still expanding set of emerging trends and technologies would not be as simple as merely providing separate, specialized guidance and objectives for them. In some cases, the conceptual underpinnings and core vocabulary used in DO-178B/ED-12B were going to need modernization to allow the extension of its fundamental principles into the world of twenty-first century software systems engineering. In particular, the software engineering field\´s evolving understanding of the nature of the inter-relationships among requirements and design information for the more complex software systems now being developed was going to require a generalization and re-conceptualization of the key DO-178B/ED-12B concepts of high-level, low-level, and derived requirements. Accordingly, a team, SG2.1, from within Sub Group 2, the Issues and Rationale group, has been working on Information Paper 217 (IP217) to propose and justify some changes to DO-178B/ED-12B in this area. Although IP217 is still very much a work in progress and has not been submitted yet for final approval by the SC-205/WG-71 plenary, it is clear that some of the issues involved overlap with similar issues at the systems engineering level that precedes the software engineering process that remains the scope of DO-178C/ED-12C. There has always been a fair amount of overlap and commonality between the two disciplines and the future of software-intensive systems in the airborne domain is more likely to see the lin- s more blurred rather than less. This paper is a work-in-progress report whose purpose is to provide the larger community with an advance look and opportunity to contribute comments and suggestions to the ongoing work of SG2.1 on IP217 and the issues and approaches to their resolution being described here.