What is my OEE?
Type the planned production time, the downtime, the ideal cycle time and the parts made. The OEE calculator shows availability, performance, quality and the OEE score.
- OEE
- 82.33%
With 90% availability, 93.83% performance and 97.5% quality, OEE is 82.33%.
- Availability
- 90%
- Performance
- 93.83%
- Quality
- 97.5%
- Run time
- 405 min
- Fully productive time
- 370.5 min
OEE: 82.33%. With 90% availability, 93.83% performance and 97.5% quality, OEE is 82.33%.
OEE by downtime
How to calculate
Works out overall equipment effectiveness (OEE) from planned production time, downtime, ideal cycle time, total parts and good parts: availability × performance × quality.
Example with the default inputs (Planned production time 450 min, Downtime 45 min, Ideal cycle time 30 s, Total parts made 760, Good parts 741): With 90% availability, 93.83% performance and 97.5% quality, OEE is 82.33%.
Method: Run time = planned production time − downtime. Availability = run time ÷ planned production time. Performance = ideal cycle time × total parts ÷ run time. Quality = good parts ÷ total parts. OEE = availability × performance × quality = good parts × ideal cycle time ÷ planned production time.
- Planned production time already leaves out planned breaks and planned stops; downtime is only the unplanned stops inside it.
- Good parts are those right the first time; reworked parts count as rejects.
- Performance cannot pass 100%: an ideal cycle time that does that is set too long.
Worked examples
Each example is checked against the calculator on every build.
- Planned production time 1,000 min, Downtime 100 min, Ideal cycle time 51.3 s, Total parts made 1,000, Good parts 990 gives Availability 90%, Performance 95%, Quality 99%, OEE 84.645%.Source: Lean Enterprise Institute, Lean Lexicon: Overall Equipment Effectiveness (availability rate × performance rate × quality rate; 90% × 95% × 99% = 84.6%), https://www.lean.org/lexicon-terms/overall-equipment-effectiveness/
- Planned production time 450 min, Downtime 45 min, Ideal cycle time 30 s, Total parts made 760, Good parts 741 gives Run time 405 min, Availability 90%, Performance 93.82716%, Quality 97.5%, OEE 82.333333%, Fully productive time 370.5 min.Source: Lean Enterprise Institute, Lean Lexicon: Overall Equipment Effectiveness (availability rate × performance rate × quality rate; 90% × 95% × 99% = 84.6%), https://www.lean.org/lexicon-terms/overall-equipment-effectiveness/ (the three rates multiplied)
- Planned production time 420 min, Downtime 0 min, Ideal cycle time 60 s, Total parts made 400, Good parts 400 gives Availability 100%, Quality 100%, Performance 95.238095%, OEE 95.238095%.Source: Lean Enterprise Institute, Lean Lexicon: Overall Equipment Effectiveness (availability rate × performance rate × quality rate; 90% × 95% × 99% = 84.6%), https://www.lean.org/lexicon-terms/overall-equipment-effectiveness/
How it works
The Lean Lexicon defines OEE as availability rate × performance rate × quality rate and says what each rate measures. Written as formulas from those definitions:
- Run time = planned production time − downtime
- Availability = run time ÷ planned production time (time left after stop losses, as a share of the scheduled time)
- Performance = ideal cycle time × total parts ÷ run time (the actual speed, total parts ÷ run time, as a share of the design speed, 1 ÷ ideal cycle time)
- Quality = good parts ÷ total parts (parts left after scrap and rework, as a share of all parts run)
- OEE = availability × performance × quality = good parts × ideal cycle time ÷ planned production time
- Fully productive time = good parts × ideal cycle time
Times may be typed in seconds, minutes or hours; the calculator works in seconds. The rates show as percents.
Exact arithmetic. Each typed time is read back as the exact decimal you typed in its unit, each result is an exact fraction, and it is rounded once for display.
Output format. Percents and minutes show 2 decimal places, rounded half up.
When there is no answer.
The checks run in this order; the first that fails gives the message.
- Downtime longer than the planned production time.
- No parts made (performance and quality have no value).
- More good parts than total parts.
- Downtime equal to the planned production time (no run time left).
- Parts that would take longer at the ideal cycle time than the run time (a performance over 100%).
Assumptions
- Planned production time already leaves out planned breaks and planned stops.
- Good parts are parts right the first time; reworked parts count as rejects.
- Planned production time is 1 second to 366 days; the ideal cycle time is at least 0.001 seconds.
Worked examples by hand
The Lean Lexicon's rates. 1,000 planned minutes, 100 minutes down, a 51.3-second ideal cycle, 1,000 parts, 990 good. Run time = 900 minutes = 54,000 s. Availability = 900 ÷ 1,000 = 90%; performance = 51.3 × 1,000 ÷ 54,000 = 95%; quality = 990 ÷ 1,000 = 99%; OEE = 0.90 × 0.95 × 0.99 = 84.645%, which the Lean Lexicon rounds to 84.6%.
One shift. 450 planned minutes (27,000 s), 45 minutes down, a 30-second ideal cycle, 760 parts, 741 good. Run time = 405 minutes = 24,300 s. Availability = 405 ÷ 450 = 90%; performance = 30 × 760 ÷ 24,300 = 22,800 ÷ 24,300 = 93.83%; quality = 741 ÷ 760 = 97.5%; OEE = 741 × 30 ÷ 27,000 = 22,230 ÷ 27,000 = 82.33%; fully productive time = 22,230 s = 370.5 minutes.
No downtime and no rejects. 7 planned hours (25,200 s), a 60-second ideal cycle, 400 parts, all good. Availability = 100%; performance = 60 × 400 ÷ 25,200 = 95.24%; quality = 100%; OEE = 95.24%.
Other questions people ask
How do you calculate OEE?
OEE = availability × performance × quality. The Lean Lexicon’s example: 90% availability, 95% performance and 99% quality give 0.90 × 0.95 × 0.99 = 84.6% OEE.
What is a shortcut for OEE?
Multiply out the three rates and most terms cancel: OEE = good parts × ideal cycle time ÷ planned production time. With 741 good parts, a 30-second ideal cycle and 450 planned minutes: 741 × 30 ÷ 27,000 = 82.33%.
What does each part of OEE measure?
Availability counts time lost to stops (breakdowns, changeovers, adjustments). Performance counts speed lost to running slower than the design speed and to short stops. Quality counts parts lost to scrap and rework. Together they cover the six big losses of total productive maintenance.
Should planned breaks count as downtime?
No. Take planned breaks, meals and planned stops off the shift first; what is left is the planned production time. Downtime is only the unplanned stops inside it.
Why can performance not be over 100%?
Performance compares the parts made with what the machine could make at its ideal speed. If the parts at the ideal cycle time add up to more than the run time, the ideal cycle time is set too long, the count is too high, or downtime is overstated. The calculator gives no answer until the numbers fit.
Do reworked parts count as good?
No. Quality counts only parts made right the first time. A part that needs rework counts as a quality loss, like scrap.