A DMAIC-Based Engineering Method for Agile–Lean Tailoring in DO-178C Software Verification

Abstract

Safety-critical avionics software development is governed by DO-178C, which imposes stringent requirements on verification, traceability, and objective evidence throughout the software lifecycle. Although traditional plan-driven lifecycles provide the discipline required for certification, continuously improving verification performance while preserving compliance remains a major challenge as software complexity increases. Existing studies have investigated Agile, Lean, and hybrid approaches in certification-constrained environments; however, they primarily focus on adapting engineering practices or reporting industrial experiences, providing limited methodological support for systematically assessing verification performance, identifying improvement priorities, and governing continuous verification improvement. This paper proposes a compliance-driven engineering method for systematically improving DO-178C verification workflows. Based on the DMAIC (Define, Measure, Analyze, Improve, Control) reasoning framework, the method systematically transforms certification objectives, lifecycle data, and project-specific compliance information into measurable assessment and improvement mechanisms. These mechanisms support systematic verification assessment, root-cause analysis, and the tailoring of Lean and Agile practices while preserving certification requirements and providing objective evidence for compliance governance. The proposed method is demonstrated through an industrial case study on requirements-based testing for Design Assurance Level A (DAL A) software. The results show improved verification readiness and verification performance while preserving traceability, verification independence, auditability, and compliance with the applicable DO-178C verification objectives. The proposed engineering method constitutes a reusable and auditable Method Engineering artifact for continuous verification improvement, validated through the presented industrial avionics case study.