Reviewed November 2026. Formulas are shown above the guide. Report an error or request a calculator.
What OEE measures
Overall Equipment Effectiveness compares what a machine produced with what it could have produced in the time it was scheduled to run. It multiplies three ratios: availability (was it running?), performance (was it running at full speed?) and quality (were the parts good?). A machine that runs all shift at full speed with no rejects scores 100%.
The single number is useful for tracking, but the value is in the breakdown. Turning each loss into minutes shows where an improvement project will pay most.
Worked example
The defaults use a classic shift: 420 minutes of planned production, 47 minutes of breakdowns, an ideal cycle of 1 second, 19,271 parts made and 18,848 good.
| Factor | Value |
|---|---|
| Availability (373 ÷ 420) | 88.8% |
| Performance (19,271 s ÷ 22,380 s) | 86.1% |
| Quality (18,848 ÷ 19,271) | 97.8% |
| OEE | 74.8% |
Of the 420 minutes, about 314 were fully productive. Breakdowns cost 47 minutes, slow cycles and small stops about 52, and defects about 7. Speed loss is the biggest item here, which is easy to miss if you only track downtime.
Getting the inputs right
- Planned production time excludes planned stops such as breaks and scheduled maintenance, but includes changeovers, which are a loss.
- Ideal cycle time is the fastest the machine can run the part, from the nameplate or the best sustained rate you have seen. Using a slow standard hides speed losses and can push performance above 100%.
- Counts must cover the same period as the time figures.
Frequently asked questions
What is a good OEE score?
85% is the widely quoted world-class benchmark. Many discrete manufacturers run between 40% and 60%. Track your own trend first.
Why is my performance above 100%?
The ideal cycle time is set too slow. Use the true fastest cycle the machine can sustain.
Are changeovers availability losses?
Yes, in standard OEE changeovers count as downtime. Planned breaks and scheduled maintenance are excluded from planned production time instead.
What is the difference between OEE and TEEP?
OEE measures against planned production time. TEEP measures against all calendar time, so it also captures unscheduled shifts and weekends.