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OEE calculator
Work out availability, performance, quality and OEE from one shift's planned time, downtime, ideal cycle time and part counts.
Result
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What OEE measures
Overall equipment effectiveness compares what a machine made with what it could have made in the time it was planned to run. It multiplies three losses together:
- Availability: time lost to stops. Run time ÷ planned production time.
- Performance: time lost to slow cycles and short stops. Ideal cycle time × total count ÷ run time.
- Quality: parts that were rejected or reworked. Good count ÷ total count.
OEE = availability × performance × quality. A machine that ran every planned minute, at its ideal cycle, with no rejects, scores 100%.
Getting honest numbers
- Leave planned breaks and scheduled maintenance out of planned production time.
- Use the fastest cycle the machine can hold for the ideal cycle time, not the average. A performance figure above 100% means the ideal cycle is set too slow.
- Count only parts that passed first time as good. Reworked parts count as rejects.
- Hand-written shift logs tend to miss short stops. Counting cycles and stops from the PLC gives a truer figure.
Need this done properly on your machines?
If you are planning automatic OEE and downtime monitoring, tell me about the job. I reply within 1 working day.