# Building Management System **Domain:** Building Automation / Facilities / Control **Doc Type:** Technical Concept Node **Maturity:** Developed ## Definition A **building management system** is a supervisory software and control layer used to monitor and coordinate building systems such as heating, cooling, ventilation, lighting, alarms and selected electrical or access functions. ## Governing Variable The system governs environmental and operational state: temperature, humidity, pressure, schedules, equipment modes, alarms and energy use. ## Material and Computational Manifestation Sensors, controllers, field networks, operator interfaces, trends and alarm systems link mechanical plant to facility operations. Local controllers may execute detailed loops while the BMS supplies schedules, setpoints, supervisory logic and historical visibility. ## Relation to Governance A BMS turns a building into a partially [[wiki/Cyber-Physical Enclosure|cyber-physical enclosure]]. In a [[wiki/Data Center|data center]], it must coexist with electrical monitoring, data-center infrastructure management and IT orchestration without allowing one representation to conceal conditions visible only in another. ## Constitutional Question and Failure Modes Optimization for energy or centralized convenience can conflict with occupant comfort, local safety and maintenance knowledge. Failure modes include sensor drift, inaccessible overrides, vendor lock-in, network compromise and automation that continues acting on stale occupancy or equipment models. ## Related Ontology [[wiki/Built Environment|Built Environment]] · [[wiki/Industrial Control System|Industrial Control System]] · [[wiki/Telemetry|Telemetry]] · [[wiki/Facility Digital Twin|Facility Digital Twin]] · [[wiki/Cyber-Physical System|Cyber-Physical System]]