Method / assumptions / examples
How this calculation works
The result is deterministic: the same measurements always return the same estimate. Here is the relationship and where real-world results can differ.
Formula
OEE = Availability × Performance × Quality
Availability compares run time with planned production time. Performance compares ideal output time with actual run time. Quality compares good count with total count.
Worked example
Examples
With 45 minutes stopped, 15,000 total units, 14,550 good units, and a 1.5 sec ideal cycle, OEE is about 75.8%.
Common mistakes
What to check before using the result
- Use a proven ideal cycle time—not the average speed from the same period being measured.
- Keep planned time, downtime, and count boundaries aligned across shifts and assets.
- If performance exceeds 100%, revisit the ideal cycle time, count units, lane multiplier, or stop-time data.
FAQ
Frequently asked questions
What is a good OEE score?
Context matters more than a universal target. Use a consistent calculation to establish the asset’s baseline, then investigate the largest of its availability, performance, or quality losses.
Should planned breaks be included?
OEE commonly excludes schedule loss before planned production time begins. Define the convention your team uses and apply it consistently.
Why can performance exceed 100%?
That usually indicates an incorrect ideal cycle time, unit conversion, lane count, or stop-time record. The calculator flags it instead of hiding the data issue.