Section 44 of 105
42. Architectural Layer Assignment
Stable section ID: S05-CON-014-SECTION-44 · 12 content blocks
Every Engineering Asset shall be assigned primarily to one System05 architectural layer.
The layer assignment shall identify:
- The asset’s principal responsibility.
- The services it provides.
- The services on which it depends.
- The Interfaces through which it interacts with other layers.
- The authority governing changes to the asset.
- The consequences of failure or unavailable service.
An asset may support several layers, but one layer shall remain its primary architectural owner. Cross-layer functions shall operate through declared Interfaces rather than hidden coupling.
A Structural Asset shall not depend on the Digital, AI, or Communication Layer for basic structural safety. Similarly, failure of a replaceable Utility, Digital, or Application Asset shall not require destructive modification of the long-life Structural Layer unless explicitly justified.
Assets shall not bypass a required architectural boundary merely to simplify implementation. Any permitted bypass shall be documented, risk-assessed, verified, and governed as an explicit architectural exception.
Layer assignment shall remain recorded in the asset’s Canonical Record, Building BIOS, and applicable Digital Twin representation.