FREE ENGINEERING TOOL · MANUFACTURING · KPIS
OEE Calculator (Overall Equipment Effectiveness)
Overall Equipment Effectiveness (OEE) measures how much of your planned production time is truly productive. It equals availability × performance × quality. Enter planned production time, downtime, ideal cycle time, total units and defective units to see each factor and the combined OEE percentage for the run.
HOW IT IS CALCULATED
The formulas
- Run time = planned production time − stop time
- Availability = run time ÷ planned production time
- Performance = (ideal cycle time × total units) ÷ run time
- Quality = (total units − defective units) ÷ total units
- OEE = availability × performance × quality
Worked example
With the default values (480 planned minutes, 45 minutes of stops, 30 s ideal cycle, 700 units, 21 defects) run time is 435 minutes. Availability is 90.6%, performance is 80.5%, quality is 97.0% and OEE is 70.7%, with 679 good units.
USING THE RESULT
What to do with the estimate
An OEE of 85% is often quoted as a world-class benchmark, but comparisons only mean something between similar processes measured the same way. Track OEE per machine over time and use the three factors to decide where to look first: stops, speed or scrap. Automated data collection from PLCs and sensors removes the manual counting errors that plague spreadsheets.
COMMON QUESTIONS
Frequently asked questions
What is OEE?
OEE, or Overall Equipment Effectiveness, is a manufacturing metric that combines availability, performance and quality into one percentage showing how effectively planned production time is used.
What is a good OEE score?
An OEE of 85% is commonly cited as a world-class target. What is realistic depends on the process, product mix and how planned downtime is treated, so trend your own results rather than chasing a single figure.
Why is my performance above 100%?
Performance above 100% usually means the ideal cycle time is set too slow or the unit count is wrong. Re-check the fastest sustainable cycle time for the product.
RELATED RESOURCES