Free tool
MTBF, MTTR & OEE Calculator
Calculate your equipment’s reliability (MTBF, MTTR) and Overall Equipment Effectiveness (OEE).
Period and downtime
Production and quality
Result: reliability and overall equipment effectiveness
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Request a maintenance strategy consultationHow the calculation works
The calculator computes: available time = period − planned downtime; actual run time = available time − failure time; MTBF = actual run time ÷ number of failures; MTTR = failure time ÷ number of failures; availability = actual run time ÷ available time; performance = produced ÷ (ideal rate × actual run time); quality = (produced − defects) ÷ produced; OEE = availability × performance × quality.
Example: a 720 h period, 40 h planned downtime, 8 failures totalling 24 h, an ideal rate of 100 units/h, 45,000 produced and 900 defects give MTBF 82.0 h, MTTR 3.0 h, availability 96.5%, performance 68.6%, quality 98.0% and OEE 64.9%.
Frequently asked questions
What is a good OEE?
85% and above is considered world class, 60% is a good level. In many factories actual OEE is lower.
What is the difference between MTBF and MTTR?
MTBF is the average time between failures, MTTR the average repair time per failure.
Where do I get the data?
From the machine log, a CMMS or production reports. If you have no data, use estimates and refine them later.
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