OEE Lab / MTBF & MTTR Calculator

MTBF & MTTR Calculator

The two numbers maintenance lives by: how long an asset runs before it fails, and how long it takes to fix. Together they give you availability. Updates as you type.

Your asset history

One asset over a defined window (e.g. last quarter).

h
Hours the asset was actually running in the window.
h
Repair time = total hours down for repair across all failures (the wrench time + waiting).
Inherent availability
-%
MTBF ÷ (MTBF + MTTR)
09599100
MTBF
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MTTR
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Failures
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Failure rate
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Cut MTTR by minutes, raise MTBF by months.

Most repair time is diagnosis - figuring out what broke and why. Fabrico shows the true cause of every stop on video the moment it happens, so repairs start faster (lower MTTR) and recurring failures get designed out (higher MTBF).

See how Fabrico improves reliability
OEE Lab is built and operated by Fabrico. Our tools stay free either way.

The formulas

  • MTBF = total operating time ÷ number of failures. Higher is better - the asset runs longer between failures.
  • MTTR = total repair time ÷ number of failures. Lower is better - failures are fixed faster.
  • Inherent availability = MTBF ÷ (MTBF + MTTR).

With 1,000 operating hours, 10 failures and 20 repair hours: MTBF = 100 h, MTTR = 2 h, availability = 100 ÷ 102 = 98.0%.

Should MTTR include waiting time?

It depends on your definition. "MTTR - repair" is wrench time only; "MTTR - restore" includes waiting for parts and technicians. Be consistent and label which you use - the waiting is often the biggest, most fixable chunk.

How does this relate to OEE?

Availability here is the reliability view of the same availability factor in OEE. Frequent short failures also overlap with micro-stops.

What's a good MTBF?

It's entirely asset- and context-specific - compare against your own trend and similar equipment, not a universal number. The goal is the direction: MTBF up, MTTR down.

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