OEE calculator
OEE (overall equipment effectiveness) shows how much of what a machine could make in the planned time it actually delivers as good parts. Enter your shift's values; the calculation runs in your browser and nothing you enter is sent anywhere.
The OEE formula
OEE = Availability × Performance × Quality. Seiichi Nakajima is widely credited with formalising OEE within Total Productive Maintenance (TPM)[1]. The three components separate three kinds of loss:
- Availability = (Planned time − Unplanned downtime) ÷ Planned time. Breakdowns, changeovers and waiting for material lower it.
- Performance = (Ideal cycle time × Total count) ÷ Run time. Slow running and minor stops lower it.
- Quality = (Total count − Defective) ÷ Total count. Scrap and rework lower it.
Worked example
In an 8-hour (480 min) shift the machine stopped for 47 minutes, the ideal cycle time is 12 seconds, 2,050 parts were made and 32 were defective. The calculator above opens with these values.
- Run time: 480 − 47 = 433 min
- Availability: 433 ÷ 480 = 90.2%
- Performance: (12 × 2,050) ÷ (433 × 60) = 94.7%
- Quality: (2,050 − 32) ÷ 2,050 = 98.4%
- OEE: 0.902 × 0.947 × 0.984 = 84.1%
How to read the result
85% is a commonly quoted target, but according to one industry publication most plants run near 60% and very few sustain 85% over a full year[1]. So the most meaningful comparison is with the same line's own history. The lowest of the three components shows where to start: low availability points to stop reasons, low performance to speed and minor stops, low quality to the source of scrap.
The limit of manual calculation
Stops written on paper can easily miss short interruptions; the loss then shows up as performance loss and the real cause is overlooked. Counting parts and stops from the machine itself brings OEE closer to reality. The BilIoT production tracking system reads the part signal and stops from the line and calculates OEE shift by shift.
Sources
Frequently asked
What is a good OEE?
The commonly quoted world-class target is 85%, usually given as 90% availability, 95% performance and 99% quality. The same publication says most plants run near 60% (source 1). What matters is the trend on your own line.
Do breaks and planned maintenance count?
Usually not. Planned production time is what remains after breaks and planned maintenance; OEE measures unplanned losses.
Why is performance above 100%?
Because the ideal cycle time was entered longer than it really is. The ideal cycle time is the shortest cycle in which the machine makes a good part, not the average cycle time.
Let's look at how it would work on your site
Tell us about your setup and we will work out which model and which measurements you need.
info@elanka.com.tr +90 312 870 11 34