What is OEE (Overall Equipment Effectiveness)?
OEE stands for Overall Equipment Effectiveness. It is a standardised performance indicator (KPI) used to measure and improve the efficiency of production equipment.
OEE quickly shows how much of the available production time is actually adding value to the production process.
🔢 How is OEE calculated?
OEE is made up of three factors:
- Availability – How much time the machine is actually running compared with the planned time
- Performance – Whether the machine is running at its maximum (theoretical) speed
- Quality – How much of the produced output meets the requirements
Formula:
OEE = Availability × Performance × Quality
Each factor is expressed as a percentage. The result is also a percentage (0–100%).
📊 Example
Suppose:
- Availability: 90%
- Performance: 95%
- Quality: 98%
Then the OEE is:
OEE = 0.90 × 0.95 × 0.98 = 0.8361 → 83.61%
An OEE of 100% means the machine runs all the time, as fast as possible and without errors — something rarely seen in practice.
🏭 Why is OEE important?
- Identifies losses such as breakdowns, changeover times, speed and rejects
- Supports continuous improvement (LEAN manufacturing, TPM)
- Makes performance comparable across machines, lines or factories
- Can be measured and reported in real time via MES systems
- Connects production with higher-level systems such as ERP or MOMS
📈 Typical OEE targets
| OEE score | Meaning |
|---|---|
| 85–100% | World class |
| 60–85% | Average / good |
| < 60% | Improvement potential (faults/losses) |
📌 In summary
OEE is a powerful KPI for measuring and improving machine effectiveness. By providing insight into availability, performance and quality, it helps to analyse production losses and optimise processes.