OEE
OEE — Overall Equipment Effectiveness
Measure and improve equipment efficiency with OEE: Availability x Performance x Quality
OEE — Overall Equipment Effectiveness
What is it for?
- Quantify how much of the equipment's theoretical capacity turns into useful production.
- Make two lines/shifts/machines comparable with a single number.
- Detect where efficiency is lost — unplanned stops (Availability), micro-stops (Performance) or scrap (Quality).
What is OEE?
OEE (Overall Equipment Effectiveness) is the industry standard for measuring manufacturing productivity. It is calculated as:
OEE = Availability x Performance x Quality
| Component | What it measures | Formula |
|---|---|---|
| Availability | Time the equipment was producing vs planned time | Operating time / Planned time |
| Performance | Actual speed vs ideal speed | (Parts produced x Ideal cycle time) / Operating time |
| Quality | Good parts vs total parts | Good parts / Total parts |
An OEE of 100% means: continuous production (Availability), at maximum speed (Performance), with zero defects (Quality).
Typical benchmarks
| OEE | Classification |
|---|---|
| < 40% | Low — significant room for improvement |
| 40-60% | Typical in plants without improvement programs |
| 60-85% | Good — plant with active continuous improvement |
| > 85% | World class |
How it works in Rela
Rela calculates OEE automatically from your sensor data and event sources:
- Connect your equipment — Data arrives via MQTT, OPC UA, Modbus, S7, or HTTP
- Configure OEE — Define ideal cycle time, planned hours, and how to count good/bad parts
- Rela calculates — Each period (shift, day, week) is calculated automatically
- Visualize — Dashboard with trends, equipment comparison, and component drill-down
Example
A packaging line working 8 planned hours:
- Had 45 minutes of downtime (format change + jam)
- Produced 4,200 units (ideal: 4,800 in operating time)
- 120 units came out defective
| Component | Calculation | Result |
|---|---|---|
| Availability | (480 - 45) / 480 | 90.6% |
| Performance | 4,200 / 4,800 | 87.5% |
| Quality | (4,200 - 120) / 4,200 | 97.1% |
| OEE | 90.6% x 87.5% x 97.1% | 77.0% |
Six big losses
OEE breaks down productivity losses into 6 categories:
| Component | Loss | Example |
|---|---|---|
| Availability | Unplanned stops | Mechanical failure, material shortage |
| Availability | Planned stops (setup) | Format change, cleaning |
| Performance | Micro-stops | Brief jams, blocked sensors |
| Performance | Reduced speed | Equipment running below ideal speed |
| Quality | Production defects | Product out of specification |
| Quality | Startup defects | Defective product when starting production |
Key benefits
- OEE calculated automatically per shift/day/week with no manual capture.
- Component breakdown (Availability / Performance / Quality) to see where efficiency leaks.
- Canonical Six Big Losses taxonomy aligned with TPM standards.
- Comparable across machines, lines and plants of the same organisation.
- Historical trend with drill-down to the specific event that moved the number.