From Individual Reviews to a Fourth Qualification Corpus: Evidence Architecture Across Engineering Reviews ER-301 to ER-399, State Variables, Scope Boundaries, Cross-Paper Couplings and Research Priorities

Engineering Reviews ER-301 to ER-399 span manufacturing physics, devices, extreme environments and evidence science. Their value is greater when the collection is treated as a connected qualification corpus in which material state, process state, measurement state and service state propagate across paper boundaries. This synthesis defines the architecture of that corpus, identifies recurring state variables, distinguishes horizontal scope boundaries from true evidence dependencies, and proposes rules for cross-paper coupling and research prioritisation. ER-400 does not replace the individual reviews; it provides the navigation and dependency layer needed to use them consistently.