OEE calculator
OEE (overall equipment effectiveness) sums up in one number how much of what a machine could produce it really produces. But the useful part is seeing where it is lost: in stoppages, in slow running or in bad parts. Enter the data for one shift and the calculator gives you the three factors and points to the biggest loss.
How it is calculated
- Availability = run time / planned production time. Run time is planned time minus downtime.
- Performance = (total parts × ideal cycle time) / run time.
- Quality = good parts / total parts.
- OEE = availability × performance × quality.
Planned production time already excludes planned breaks, such as rest periods or shifts with no production. Downtime covers the unplanned stops and the ones you want to improve: breakdowns, changeovers, waiting for material.
Example
With the calculator’s default data: availability 405 / 450 = 90 %; performance 680 × 30 / (405 × 60) ≈ 84 %; quality 660 / 680 ≈ 97 %. OEE ≈ 73 %. The biggest loss is in performance: minor stops and slow running.
How to use the result
- Availability loss: look at repeat breakdowns, long changeovers and waiting for material.
- Performance loss: look for minor stops (a badly adjusted sensor, jams) and speeds below rated speed.
- Quality loss: find out at which station and why bad parts are made.
85 % is often quoted as world class, but what matters is the trend of your own machine and tackling the biggest loss first. Adjusting a sensor often gains more than buying a new machine.