Key takeaways
- OEE = Availability × Performance × Quality. Each factor answers a different question.
- Availability = did it run? Performance = did it run at full speed? Quality = were the parts good?
- Always improve your lowest factor first; the others are already closer to their limit.
- Performance is the most under-measured, because micro-stops hide inside it.
OEE is one number, but you cannot improve a number, you improve its causes. That is what the three factors are for: they split the loss into Availability, Performance and Quality so you know exactly where to push. (New to OEE? Start with What is OEE?)
The three factors at a glance
| Factor | Formula | Answers | World-class |
|---|---|---|---|
| Availability | Run Time ÷ Planned Production Time | Did it run when it should? | ~90% |
| Performance | (Ideal Cycle × Total Count) ÷ Run Time | Did it run at full speed? | ~95% |
| Quality | Good Count ÷ Total Count | Were the parts good first time? | ~99.9% |
Availability
The share of planned time the machine was actually running. It is dragged down by the two availability losses: breakdowns (unplanned stops) and setup & changeovers. To raise it: cut breakdowns with predictive maintenance and faster repair (MTTR), and shrink changeovers with SMED.
Performance
How fast it ran versus how fast it could. Dragged down by minor stops (micro-stops) and reduced speed. This is the sneaky factor: those losses are too short to log, so they show up as an unexplained gap rather than identified downtime. On many lines it is the single biggest recoverable loss, see the hidden factory. Performance can read over 100% only if your ideal cycle time is set wrong, fix the input, not the machine.
Quality
The share of parts that were good first time. Rework counts as a defect, not a good unit. Dragged down by process defects (steady-state scrap/rework) and reduced yield (rejects at startup/changeover). To raise it: SPC, process control and root-cause work on the defect modes.
Enter your shift numbers and the calculator shows Availability, Performance and Quality separately, plus your biggest opportunity.
Which to attack first
Improve your lowest factor. The maths makes this obvious: because OEE multiplies them, lifting a factor that is at 60% returns far more than polishing one already at 95%. A worked example: at 90% × 70% × 99% = 62% OEE, Performance (70%) is the lever. Chasing the already-high Quality would barely move OEE; fixing the micro-stops behind Performance moves it a lot.
Map each loss to its factor with the six big losses, then go after the pair under your weakest factor.
The common thread
All three factors depend on measuring the line accurately, and Performance especially falls apart when short stops go uncounted. The partner we recommend, , reads OEE straight from the PLC, shows the true cause of micro-stops on video, and routes a work order, so each factor becomes visible and fixable. It is EU-built with EU data residency and holds ISO 27001 / 20000-1 / 9001 (supports audit-readiness). Fabrico is a partner we recommend; the tools here are free regardless.
Do the factors have to be multiplied?
Yes. OEE = A × P × Q. That is why a low factor hurts so much, and why you target the lowest one.
What is a good number for each?
The world-class references are roughly 90% Availability, 95% Performance and 99.9% Quality, which multiply to about 85% OEE. Compare to your own trend first.
Where does the hidden factory sit?
Inside Performance. Micro-stops and speed loss are the performance losses, and they are the most under-measured. More here.