Planned vs Reactive Maintenance

Moving from Reactive to Planned: The Foundation of Building Asset Management

Building maintenance falls into three fundamental categories: preventive (time-based), predictive (condition-based) and corrective (reactive). The balance between these categories determines not only the physical condition of a building but also its operational cost, occupant safety, energy performance and long-term asset value. Globally, best-practice facility management targets an 80/20 ratio of planned to reactive maintenance. In Bangladesh, most buildings operate almost entirely on a reactive basis — repairing systems only after they fail.

Three Maintenance Strategies

1. Preventive Maintenance (Time-Based / Planned Preventive Maintenance — PPM)

Preventive maintenance is performed on a fixed schedule regardless of equipment condition. It is based on manufacturer recommendations, industry standards and operational experience. Examples include: quarterly filter changes on air handling units, six-monthly fire alarm testing per NFPA 72, annual thermographic surveys of electrical switchgear, and monthly generator test runs. The schedule is derived from equipment manufacturer recommended maintenance intervals, statutory requirements (fire system testing, lift inspections) and asset criticality.

PPM is the backbone of any organised maintenance programme. It aims to prevent failures before they occur, maintain equipment at designed efficiency levels and ensure statutory compliance. ISO 55001 (Asset Management) requires organisations to establish planned maintenance activities as part of their asset management system, with clear linkages between maintenance strategy and organisational objectives.

2. Predictive Maintenance (Condition-Based)

Predictive maintenance uses monitoring data and condition assessment to determine when intervention is needed. Rather than replacing a component on a fixed schedule, it is replaced when measured conditions indicate approaching failure. Examples include: vibration analysis on rotating equipment (pumps, fans, motors) to detect bearing deterioration before failure; oil analysis on transformer insulating oil to detect degradation; infrared thermography on electrical connections to identify hot spots before they cause faults; ultrasonic testing of steam traps to detect failures.

ASHRAE maintenance guidelines encourage condition-based approaches for high-value equipment where monitoring technology provides reliable early warning. Predictive maintenance is more cost-effective than preventive for equipment where failure patterns are variable, but requires investment in monitoring equipment and trained personnel.

3. Corrective Maintenance (Reactive / Run-to-Failure)

Corrective maintenance is performed only after equipment has failed. It is appropriate for non-critical, low-cost items where the consequence of failure is minor and the cost of prevention exceeds the cost of repair. It is inappropriate for life safety systems (fire alarms, emergency lighting, sprinklers), vertical transport (lifts), primary electrical distribution and any system whose failure creates safety risks or significant business disruption.

FM Key Performance Indicators (KPIs)

Effective facility management requires measurement. The following KPIs are widely used to assess maintenance programme effectiveness:

CMMS and CAFM Systems

A Computerised Maintenance Management System (CMMS) or Computer-Aided Facility Management (CAFM) system is the tool that enables planned maintenance at scale. These systems manage work order generation (automatically creating PPM tasks on schedule), work order tracking (recording completion, time, parts and cost), asset registers (documenting all equipment with specifications, location, warranty and maintenance history), spare parts inventory and reporting/analytics (generating the KPIs above). Without a CMMS/CAFM, maintenance programmes rely on paper records, spreadsheets and memory — all of which degrade in reliability as building complexity increases.

Equipment Manufacturer Recommended Maintenance Intervals

Every significant piece of building equipment comes with manufacturer-specified maintenance requirements. Typical intervals include:

• Chillers: Daily log readings, monthly refrigerant checks, quarterly condenser cleaning, annual comprehensive service including oil analysis and electrical testing
• Air Handling Units: Monthly filter inspection, quarterly filter replacement (varies by environment), six-monthly belt inspection/replacement, annual coil cleaning and motor servicing
• Generators: Weekly no-load test run (15–30 minutes), monthly load test, quarterly oil and filter change, annual comprehensive service including load bank testing
• Lifts: Monthly inspection and lubrication, quarterly safety device testing, annual comprehensive inspection per local regulations
• Electrical switchgear: Annual visual inspection, biennial thermographic survey, five-yearly comprehensive testing including protection relay calibration
• Fire alarm systems: Weekly panel check, monthly detector testing (sample), six-monthly full system test per NFPA 72, annual comprehensive inspection
• Fire pumps: Weekly churn test, monthly full-flow test, annual comprehensive test per NFPA 25

Transitioning from Reactive to Planned Maintenance

For buildings currently operating on a purely reactive basis, the transition to planned maintenance should be prioritised by criticality and safety impact:

1. Life safety systems first: Fire alarm, fire suppression (sprinklers, extinguishers), emergency lighting, smoke ventilation, fire doors — these must be tested and maintained on schedule because failure directly affects life safety
2. Vertical transport: Lifts and escalators — statutory inspection requirements exist, and failure causes both safety risk and operational disruption
3. Generators and emergency power: These systems must work when needed — regular testing is the only way to confirm readiness
4. Electrical distribution: Switchgear, distribution boards, earthing systems — electrical faults cause fires, electrocution and business disruption
5. HVAC and plumbing: While less immediately life-threatening, unplanned failures of these systems cause occupant discomfort, water damage and potential mould/health issues

Bangladesh Context

Most commercial buildings in Bangladesh operate on a predominantly reactive maintenance model. Common characteristics include: no formal PPM schedule, maintenance records kept on paper (if at all), no CMMS/CAFM system, spare parts purchased after failure rather than stocked, and maintenance staff often undertrained for the equipment they manage. Fire system testing is particularly deficient — many buildings with installed fire alarm and sprinkler systems have never tested them after initial installation.

The reasons are primarily cultural and economic: maintenance is viewed as an expense rather than an investment, building owners underestimate the cost of reactive failures (which is typically 3–5 times the cost of planned prevention), and there is limited regulatory enforcement of maintenance obligations. Transitioning even a portion of maintenance activity from reactive to planned — starting with life safety systems — can significantly reduce risk and total cost of ownership.

Practical Considerations

Implementing a maintenance programme does not require expensive software from day one. A simple spreadsheet-based PPM schedule — listing every asset, its required maintenance tasks and their frequencies — is a meaningful starting point. The critical elements are: identifying all assets, defining what maintenance each requires (from manufacturer manuals and standards), scheduling tasks at appropriate intervals, recording completion and tracking compliance. A CMMS becomes valuable when the volume of assets and tasks exceeds what can be reliably managed manually, typically above 500 assets or 100 monthly PPM tasks.