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Mean time between failures

(also MTBF)

Mean time between failures definition

Mean time between failures (MTBF) is a way to measure how long a mechanical or electronic system usually runs before it fails. It estimates how reliable a product or system is and is typically expressed in hours.

See also: mean time to failure, mean time to repair, mean time to recovery, mean time to respond

How mean time between failures works

  1. 1.MTBF calculation starts with collecting data on how long a system operates before it fails.
  2. 2.Each failure instance is recorded along with the time it occurred.
  3. 3.MTBF is calculated by dividing the total time the system was running by the number of failures. For example, if a system operated for 1000 hours and experienced 10 failures, the MTBF would be 1000/10 = 100 hours.

Variations of mean time between failures

  • Mean time to failure (MTTF). Used for non-repairable systems, where the focus is on the time until the first failure.
  • Mean time to repair (MTTR). Measures how long it takes, on average, to fix a failed component or system.
  • Mean time between system incidents (MTBSI). Looks at both failures and other problems that affect system performance but are not considered failures.

Uses of mean time between failures

  • Electronics. MTBF is crucial for estimating how long products like circuit boards and power supplies will last.
  • Manufacturing. MTBF is applied to measure the reliability of machinery and equipment. It helps plan maintenance, reduce downtime, and improve efficiency.
  • Consumer goods. Manufacturers use MTBF to predict how long products like home appliances and vehicles will work.
  • Aerospace and defense. MTBF is critical for making sure equipment like aircraft parts and defense systems are reliable and safe.
  • Energy. MTBF helps keep power systems running reliably.
  • Software engineering. Although traditionally a hardware metric, MTBF is also used to estimate how often software might fail.
  • Project planning and risk management. In various industries, MTBF data helps plan for when equipment might fail and how to deal with it.