Use when scoping European space software work per the ECSS series: classify space software criticality (A-D) from failure consequence, size the assurance and verification rigor for the category, gate lifecycle phases (requirements through acceptance) on their review records, and scope heritage-reuse evidence. ECSS-E-ST-40C Rev.1 governs software engineering, Q-ST-80C Rev.2 software product assurance, and the series is the European space procurement baseline. Trigger: ECSS, space software, E-ST-40C, software criticality, product assurance, Q-ST-80C, heritage software, space software lifecycle, software verification.
