📖 Plant Engineering Encyclopedia

Maintenance & Reliability Metrics Glossary

Interactive formulas, world-class benchmark targets, and technical implementation guides for key maintenance engineering performance indicators.

Maintenance Velocity MTTR

The average clock time required to diagnose, repair, and re-commission a failed machine back into production.

Formula: Total Corrective Maintenance Downtime Hours / Number of Breakdown Incidents

Asset Reliability MTBF

The fundamental metric of asset reliability predicting the expected operating duration between machine failures.

Formula: Total Operating Uptime Hours / Number of Unplanned Breakdown Failures

Operational Productivity OEE

The gold standard manufacturing metric quantifying the percentage of planned production time that is truly productive.

Formula: Availability (%) × Performance (%) × Quality (%)

Labor Efficiency Tool Time

The percentage of a maintenance craftsperson's shift spent actively turning wrenches on machinery versus in transit or searching for parts.

Formula: (Direct Hands-On Repair Minutes / Total Scheduled Shift Minutes) × 100

Predictive Reliability P-F Curve

The visual representation of asset degradation illustrating how early condition monitoring intercepts catastrophic functional breakdowns.

Formula: Time Elapsed Between Initial Detectable Defect (P) and Functional Failure (F)

Maintenance Strategy PMP

The ratio measuring how proactively maintenance labor is deployed versus reactive firefighting.

Formula: (Scheduled Preventive Maintenance Hours / Total Maintenance Labor Hours) × 100

Want to Automate These KPIs in Your Plant?

Modern CMMS platforms automatically generate MTTR, MTBF, and Wrench Time charts directly from technician work orders.