Systems Maintenance: Building Systems and Maintenance Administration
Core concepts
A facilities manager must know how each building system fails and how its maintenance is triggered. Understand HVAC (air handling units, chillers, boilers, cooling towers, controls), electrical distribution (switchgear, panelboards, transformers, emergency generators, UPS), plumbing (domestic water, sanitary drainage, backflow prevention), fire protection (sprinklers, alarms, standpipes), elevators, and building envelope. Know the difference between preventive maintenance (PM) - scheduled, calendar- or runtime-based tasks - and predictive maintenance (PdM) - condition-based work driven by vibration analysis, thermography, oil analysis, or ultrasonic testing. Understand reactive/corrective work and how a work order system captures labor, parts, and history. Learn the role of a computerized maintenance management system (CMMS) in scheduling, backlog tracking, and asset records. Know mean time between failures (MTBF) and mean time to repair (MTTR) as reliability measures. Understand life-cycle cost analysis and the repair-versus-replace decision.
Traps in questions
Watch for wording that confuses preventive with predictive: a calendar-based belt inspection is PM, not PdM. Questions often describe a task triggered by a vibration reading and expect "predictive." Another trap is mixing MTBF (reliability, time between failures) with MTTR (maintainability, time to restore). Also distinguish a work order from a service request; the request is the intake, the work order is the authorization and record. Do not confuse a backflow preventer (plumbing cross-connection protection) with a check valve in fire protection.
Worked rule of thumb
Compute availability as MTBF ÷ (MTBF + MTTR). If a chiller runs 900 hours between failures and averages 100 hours to repair, availability = 900 ÷ 1,000 = 90%. Use this to justify PdM investment: cutting repair time to 50 hours raises availability to 94.7%.