Both predictive and preventive maintenance are proactive strategies that aim to prevent equipment failures before they happen. The key difference is how they determine when maintenance is needed: preventive maintenance follows a fixed schedule, while predictive maintenance relies on real-time condition data. Understanding both approaches helps you build the optimal maintenance strategy for your operations.
How Each Strategy Works
Preventive Maintenance (PM)
Approach: Schedule-based. Maintenance is performed at fixed intervals regardless of equipment condition.
Triggers: Calendar time (every 90 days) or usage meters (every 500 hours).
Example: Change oil every 3 months or 3,000 miles, whichever comes first.
Data needed: Manufacturer recommendations, industry standards, operational experience.
Predictive Maintenance (PdM)
Approach: Condition-based. Maintenance is performed when data indicates it is actually needed.
Triggers: Sensor readings, vibration levels, temperature anomalies, oil degradation.
Example: Change oil when oil analysis shows contamination or viscosity degradation.
Data needed: Sensors, monitoring equipment, historical baselines, analytical tools.
Comparing the Two Strategies
Cost
Preventive: Moderate cost. Some maintenance may be performed too early (wasting parts and labor) or too late (allowing a failure). Implementation cost is low.
Predictive: Lower maintenance cost per task (only done when needed), but higher upfront investment in sensors, monitoring equipment, and data analysis capabilities.
Complexity
Preventive: Relatively simple. Set schedules, assign technicians, track completion. Most organizations can implement PM quickly with standard CMMS software.
Predictive: More complex. Requires sensor installation, data collection infrastructure, baseline establishment, and analytical expertise to interpret condition data meaningfully.
Effectiveness
Preventive: Significantly better than reactive maintenance. Reduces unplanned downtime 30-50%. May over-maintain or under-maintain some assets since schedules are estimates.
Predictive: The most targeted approach. Maintenance happens at exactly the right time based on actual equipment condition. Can reduce maintenance costs an additional 8-12% beyond PM alone.
When to Use Each Strategy
Preventive Maintenance Is Best For
Assets where failure modes are time- or usage-based (filters, belts, lubricants).
Equipment where condition monitoring is impractical or too expensive.
Regulatory-mandated inspections with fixed frequencies.
Organizations building their first formal maintenance program.
Lower-cost assets where the sensor investment is not justified.
Predictive Maintenance Is Best For
High-value, critical assets where downtime is extremely costly.
Equipment with measurable degradation signatures (vibration, heat, noise).
Assets where scheduled maintenance is disruptive to production.
Organizations with mature PM programs looking to optimize further.
Equipment with automated data feeds or IoT sensor capabilities.
The Best Approach: Use Both
The most effective maintenance programs combine both strategies. Start with a strong preventive maintenance foundation, then layer predictive techniques onto your most critical and expensive assets.
Getting Started
Step 1: Build a PM Foundation
If you do not already have a structured preventive maintenance program, start there. Implement CMMS software, establish schedules for all critical assets, and build a checklist-driven inspection program.
Step 2: Identify PdM Candidates
Rank your assets by criticality and failure cost. The top 10-20% of assets are typically the best candidates for predictive maintenance investment.
Step 3: Implement Condition Monitoring
Install sensors or establish monitoring routines for selected assets. Common techniques include vibration analysis, thermal imaging, oil analysis, ultrasonic testing, and motor current analysis.
Step 4: Integrate with Your CMMS
Feed condition data into your PM software to establish baselines, track trends, and automatically trigger work orders when thresholds are exceeded.
Ecesis Maintenance Software Solutions
Preventive Maintenance
Work orders, PM scheduling, and asset management
Inspection Software
Mobile inspections, checklists, and compliance tracking
Task Management
Corrective actions, assignments, and automated reminders
Document Management
Equipment manuals, SOPs, and safety procedures
Training Management
Track maintenance team certifications and competency
Mobile App
Access work orders and equipment data from anywhere
