OEE Calculator

Run time = Planned production time − Downtime
Availability = Run time / Planned production time
Performance = (Ideal cycle time × Total count) / Run time
Quality = Good count / Total count
OEE = Availability × Performance × Quality

• Planned production timescheduled time, with planned shutdowns and breaks already excluded
• Downtimeunplanned stops plus changeovers during the scheduled window
• Ideal cycle timethe fastest sustainable time per part, from the nameplate rate
• Total countall parts produced, good and defective
• Good countparts passing first time, with no rework

• The whole calculation collapses to Good count × Ideal cycle time / Planned production time, which gives 780 × 0.5 / 480 = 81.25% here. If your three factors do not reproduce that shortcut, one of the inputs is defined inconsistently.
• 85% is the widely quoted world-class benchmark, built from 90% availability, 95% performance and 99% quality. Most discrete manufacturers measuring honestly for the first time land near 60%, and a first measurement above 90% almost always means planned production time was defined too generously.
• Performance above 100% is a data error, not a triumph. It means the ideal cycle time is set slower than the line genuinely runs, and it silently inflates OEE. Reset the ideal cycle to the best sustained rate ever demonstrated, not to a conservative planning figure.
• Rework counts as a defect. Quality measures first-pass yield, so a part that needed touching up before it shipped belongs outside the good count even though it eventually sold.
• OEE is a machine metric and only means something at a constraint. Driving OEE up on a non-bottleneck asset builds inventory rather than throughput, which is why TEEP, adding the calendar-time question of whether you should be running at all, is the better number at plant level.