Core Reliability
OEE Calculator
Overall Equipment Effectiveness from availability, performance, and quality — and which of the six big losses is costing you most.
OEE = A × P × QInput Parameters
Availability
Performance
Quality
Results
Overall OEE
OEE Benchmark
What is OEE?
Overall Equipment Effectiveness (OEE) is a manufacturing performance metric that identifies the percentage of manufacturing time that is truly productive. It measures the efficiency of a single machine or process by combining three factors:
- Availability: equipment uptime against planned production time
- Performance: speed and cycle-time efficiency
- Quality: good parts against total parts produced
Broken down this way, OEE points to which of the six big losses to attack first and gives a baseline for improvement.
OEE formula
OEE = Availability × Performance × QualityOperating time ÷ Planned production time(Ideal cycle time × Total count) ÷ Operating timeGood count ÷ Total countPlanned production time excludes planned stops such as breaks; only unplanned downtime counts against availability.
OEE calculation example
One 8-hour shift on a production line:
| Input | Value |
|---|---|
| Shift length | 480 min |
| Planned downtime (breaks) | 40 min |
| Unplanned downtime | 47 min |
| Ideal cycle time | 1.0 s / piece |
| Total count | 19,271 pieces |
| Rejects | 423 pieces |
(480 − 40 − 47) ÷ (480 − 40) = 393 ÷ 440 = 89.3%(1.0 s × 19,271) ÷ (393 min × 60) = 81.7%18,848 ÷ 19,271 = 97.8%89.3% × 81.7% × 97.8% = 71.4%Performance is the weakest factor here, so minor stops and reduced speed are the first place to look.
The six big losses
| OEE factor | Loss | Description |
|---|---|---|
| Availability | 1. Equipment failures | Unplanned stops due to breakdowns |
| Availability | 2. Setup & adjustments | Changeovers and setups |
| Performance | 3. Idling & minor stops | Short stops, typically under 5 minutes |
| Performance | 4. Reduced speed | Running slower than the ideal cycle time |
| Quality | 5. Process defects | Defective parts during stable production |
| Quality | 6. Startup rejects | Defective parts during startup and warm-up |
OEE benchmarks
| OEE | Level | Meaning |
|---|---|---|
| 85%+ | World class | Exceptional performance with minimal losses |
| 70 – 85% | Good | Above average with room for improvement |
| 60 – 70% | Fair | Average, with significant opportunities |
| < 60% | Poor | Needs immediate attention |
Commonly quoted typical ranges by industry (orientation only — compare against your own baseline):
| Industry | Typical OEE |
|---|---|
| Automotive | 60 – 75% |
| Food & beverage | 50 – 65% |
| Pharmaceuticals | 65 – 80% |
| Electronics | 70 – 85% |
| Packaging | 55 – 70% |
| Textiles | 45 – 60% |
How to improve OEE
| Factor | Typical actions |
|---|---|
| Availability | Preventive and predictive maintenance, faster changeovers (SMED), better maintenance planning, standard procedures |
| Performance | Eliminate minor stops, optimise machine settings, improve material flow, reduce cycle-time variation |
| Quality | Statistical process control, mistake-proofing, shorter warm-up, regular calibration, better raw material |