The facility management glossary every maintenance professional needs.
From MTBF to OEE to Permit to Work — clear, practical definitions for every term your facility team uses. Bookmark this page.
Essential FM & CMMS Terms Explained
Written for facility managers, maintenance engineers, and operations leaders — not for academic journals.
CMMS
Computerised Maintenance Management System. Software that centralises maintenance operations — work orders, assets, PM scheduling, and reporting — in one platform. Modern CMMS includes AI and autonomous agents.
CAFM
Computer-Aided Facility Management. Broader than CMMS — includes space planning, lease management, and move management alongside maintenance. FacilityFlow combines CAFM + CMMS + AI in one platform.
MTBF
Mean Time Between Failures. Total uptime divided by number of failures. If an asset runs 8,760 hours per year and fails 3 times, MTBF = 2,920 hours. Higher MTBF = more reliable asset.
MTTR
Mean Time To Repair. Average time from failure detection to full restoration. Includes diagnosis, parts sourcing, and repair. Target: minimise MTTR through spare parts availability and technician skill matching.
OEE
Overall Equipment Effectiveness. Availability × Performance × Quality. The plant manager's single KPI for asset productivity. OEE of 85% is world-class. FacilityFlow calculates OEE live from work order and downtime data.
TCO
Total Cost of Ownership per Asset. Purchase price + installation + maintenance + energy + downtime costs − residual value. FacilityFlow's Asset Lifecycle Agent tracks TCO from day one and recommends repair vs. replace.
Permit to Work (PTW)
A formal safety system that ensures hazardous work is properly planned, authorised, and documented. LOTO, confined space, hot work. No technician can start without an approved PTW. FacilityFlow enforces this digitally.
LOTO
Lockout/Tagout. A safety procedure that ensures dangerous machinery is properly shut off and cannot be started before maintenance is completed. Required by OSHA and equivalent bodies globally. FacilityFlow enforces LOTO digitally.
Predictive Maintenance
Using data and AI to predict when equipment will fail — before it happens. FacilityFlow's Predictive Maintenance Agent scores failure probability at 7, 14, and 30-day windows using IoT sensor data, historical MTBF, and condition trends.
Preventive Maintenance
Scheduled maintenance performed at fixed intervals regardless of asset condition. Prevents failures through regular servicing. FacilityFlow automates PM scheduling by date, runtime hours, or AI recommendation.
IoT in FM
Internet of Things — sensors embedded in equipment that stream real-time data (temperature, vibration, pressure, energy). FacilityFlow connects to IoT via MQTT, BACnet, and Modbus, and uses sensor data to drive predictive maintenance.
AI Agents in CMMS
Autonomous software modules trained for specific operational domains. FacilityFlow's 23 agents include Predictive Maintenance, SLA Monitor, Compliance Guardian, and Morning Briefing — running 22 autonomous operations every day.
See every one of these concepts in action inside FacilityFlow.
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