Evidence-Based Development - Applying Safety Engineering Techniques to the Progressive Assurance and Certification of Complex Systems

This paper presents evidence-based development (EbD), an approach to progressive system assurance that is confidence-based and deeply integrated with the development process. EbD draws inspiration from requirements management, risk management, and from the claim-evidence-argument paradigm well known in the safety engineering domain. The ideas are applied not just to safety, but to the broader concept of system fitness-for-purpose. EbD provides an evidential backbone for assurance, recognising that assurance is a progressive activity that begins at the very start of the system lifecycle. Evidence is accumulated where confidence is most lacking, beginning with design verification in the earliest stages of development, through design fulfilment from test results in the later stages. It caters for assurance and certification evidence arising in many different forms from diverse sources and approaches throughout the lifecycle. The paper will also describe the work undertaken under the auspices of a UK DBERR Technology Programme to apply EbD to the certification of systems to RTCA/DO-178B. It will argue that EbD has features that address particular parts of the standard in new ways.