Building BIOS Architecture

The Dependency Map identifies which building entities require other entities, resources, services, or conditions to function safely and correctly.

Dependency types may include:

structural support;

electrical supply;

grounding;

water supply;

drainage;

ventilation;

communication;

control authorization;

sensing;

time synchronization;

cooling;

environmental protection;

fire protection;

software service;

human supervision;

emergency backup.

Each dependency shall identify:

dependent entity;

required entity or capability;

dependency type;

minimum acceptable capability;

criticality;

permitted interruption duration;

fallback resource;

behavior upon loss;

restoration sequence.

Dependencies shall be classified as:

mandatory;

optional;

conditional;

redundant;

temporary;

commissioning-only;

emergency-only.

The BIOS shall use the Dependency Map before authorizing:

shutdown;

isolation;

maintenance;

removal;

replacement;

software update;

configuration change;

emergency action.

Circular dependencies shall be identified and evaluated. A startup sequence shall not require two services to wait indefinitely for each other.

Common dependencies shall be visible. Two nominally redundant systems shall not be represented as independent if they share the same power supply, communication gateway, cooling system, or control service.

Loss of a dependency shall cause affected entities to transition according to their defined degraded, isolated, or safe-state behavior.