How to use this calculator
- Enter or choose planned production time.
- Enter or choose stop time (breakdowns, changeovers).
- Enter or choose ideal cycle time.
- Enter or choose total count (good + rejects).
- Enter or choose good count.
- The oEE updates as you type. Use Copy result or Share to keep it.
Method
Availability = Run time ÷ Planned time; Performance = Ideal cycle × Total count ÷ Run time; Quality = Good ÷ Total; OEE = A × P × Q
- Run time
- planned time minus stop time
- Ideal cycle
- theoretical fastest time per unit
Worked example
- Run time = 420 − 47 = 373 min; Availability = 373 ÷ 420 = 88.81%.
- Performance = 1 s × 19,271 ÷ (373 × 60 s) = 86.11%.
- Quality = 18,848 ÷ 19,271 = 97.80%.
- OEE = 0.8881 × 0.8611 × 0.9780 = 74.79%.
The line ran at 74.79% OEE: about 314 of the 420 planned minutes were fully productive.
What the result means
The lowest of the three factors shows where most time is lost: stops (availability), slow running and small stops (performance) or rejects (quality). Track OEE on the same machine over time rather than comparing different machines.
Assumptions and limits
- Planned breaks are excluded from planned production time.
- The ideal cycle time is the true design or best demonstrated speed.
- If the ideal cycle time is set too slow, performance exceeds 100%; the calculator rejects that rather than hide it.
Questions
What is a good OEE?
It depends on the process. Benchmarks are often quoted but vary widely by industry, so track your own trend.
Is OEE the same as utilisation?
No. Utilisation only measures run time; OEE also accounts for speed and quality losses.