Maintenance Awareness: Strategy, Metrics, and Safe Intervention
Why a task was scheduled, and what the number means
Three strategies. Reactive (run-to-failure) is acceptable only for cheap, non-critical items. Preventive maintenance is time- or usage-based: lubrication routes, filter changes, belt inspections on a calendar or hour meter. Predictive (condition-based) maintenance acts on actual machine condition - vibration analysis, thermography, oil analysis, ultrasonic leak detection, and trended temperature or pressure. A rising vibration trend crossing an alert level triggers work; that is predictive, not preventive.
TPM and the operator's role. Total Productive Maintenance pushes basic care to the operator: clean, inspect, lubricate, tighten, and tag abnormalities. Autonomous maintenance frees skilled technicians for diagnosis while catching small faults early. Every task belongs on a work order in the CMMS, with history that exposes repeat failures.
Metrics. MTBF (mean time between failures) measures reliability - higher is better. MTTR (mean time to repair) measures maintainability - lower is better. Availability = MTBF ÷ (MTBF + MTTR). A machine running 90 hours between failures with a 10-hour repair is available 90 ÷ 100 = 90%. Trap: cutting MTTR raises availability as surely as raising MTBF, and it is often cheaper.
Safety during maintenance. Maintenance is when lockout/tagout matters most: isolate, lock, tag, release stored energy, and verify zero energy. Never bypass an interlock or remove a guard to save time - defeated guards are a leading cause of serious injury.
Rule of thumb: if a failure repeats, stop repairing and start investigating. The second failure says the root cause was never found.