Maintenance Strategies

Study Notes

Involves running equipment until it fails, then repairing or replacing it
Often used for non-critical or inexpensive equipment
Advantages: no scheduling required, some equipment cheaper to replace than repair
Disadvantages: unplanned production losses, catastrophic equipment failure, high spares inventory costs, secondary machinery damage

Planned maintenance performed at regular intervals (e.g., daily or every 2-3 days)
Examples include greasing conveyor belt bearings
Advantages: longer machine life, reduced production downtime, fewer spares required
Disadvantages: potential unplanned production losses, unnecessary repairs or replacements

Involves inspecting or testing equipment to determine its condition
Uses condition monitoring equipment (e.g., vibration monitoring, contamination monitoring)
Example: oil sampling in vehicles to predict engine, transmission, or differential overhaul
Advantages: reduces unscheduled downtime, extends maintenance repair intervals, minimizes unnecessary repairs
Disadvantages: high initial investment, potential lack of commitment to training, inspection data may not be analyzed

Combination of various maintenance strategies with a single plan and set timeline
Often referred to as "general overhauls" or "shutdown maintenance"
Examples: Eskom's "outage" or "shutdown" maintenance, where a plant subsystem is disassembled and repaired over 2-5 months

Aims to identify and prevent issues before they occur (deterioration prevention)
Focuses on proactive and preventative techniques to improve equipment reliability
Goals: increase Overall Equipment Effectiveness (OEE), maintain equipment in good condition without interfering with daily processes
OEE factors: Performance, Availability, Quality
Autonomous Maintenance: operators perform daily inspections, maintenance, and repairs, giving them greater "ownership" of equipment.