KEY TAKEAWAYS
- Control the reporting denominator.
- Validate cycle times and count sources.
- Label missing inputs and avoid presenting partial OEE as complete.
In this resource
Agree on planned production time
Decide which periods are included in the reporting window. Document how breaks, planned stops and changeovers are treated before comparing shifts or machines.
Changing the denominator can change OEE without changing the process. Keep reporting definitions controlled and explain changes in historical comparisons.
Calculate the three factors
Availability = run time ÷ planned production time. Performance = ideal cycle time × total count ÷ run time. Quality = good count ÷ total count. OEE is their product.
Use consistent units. Validate the ideal cycle time for the product or job and define where total and good counts are measured.
Work through an illustrative shift
For the example below, planned production is 480 minutes and recorded run time is 420 minutes. Ideal cycle time is one minute per part, total output is 360 parts and good output is 342 parts.
Availability is 87.5%, performance is about 85.71%, and quality is 95%. Multiplying the unrounded factors gives OEE of 71.25%. The values are illustrative, not a customer result.
Handle incomplete inputs
When quality counts or a defensible ideal cycle time are unavailable, begin with machine states and utilization. Label a partial reporting model clearly.
Use the timeline and reason codes to investigate the result. The score is a summary of the defined model, not a complete explanation of every production loss.
Worked example — illustrative shift data
| Input / result | Value |
|---|---|
| Planned production time | 480 minutes |
| Run time | 420 minutes |
| Ideal cycle time | 1 minute / part |
| Total count | 360 parts |
| Good count | 342 parts |
| Availability | 87.5% |
| Performance | 85.71% (rounded) |
| Quality | 95% |
| OEE | 71.25% |
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