MTBF (Mean Time Between Failures) is a measure of the reliability of a device or machine. It means the average time between subsequent failures of a device or machine. It is one of the key performance indicators used in the TPM system in many industries and allows companies to measure the reliability of the production process and the availability of operated devices and machines.
A high score means that the device is more reliable because failures occur less often and the mean time between failures is longer. This means that the company has fewer downtimes, fewer costly repairs, and production processes are more stable.
On the other hand, a low MTBF score means that the device is less reliable, failures occur more often, leading to longer downtime and higher costs associated with repairs or replacement of the device.
Therefore, monitoring the MTBF indicator is important so that the company can continuously assess the reliability of its devices and machines and take actions that will allow to increase this indicator. Improving the reliability of devices can lead to lower costs, increased efficiency and improved competitiveness of the company on the market.
It is worth noting that MTBF is a statistical indicator that does not guarantee that a given system or device will not fail within a specified time. In addition, MTBF does not take into account the time needed to repair or replace a failed component, which can affect the time the system or device is down.
When calculating MTBF, follow these steps:
- Collect data on system or device uptime and failure times. Make sure the data is comprehensive and accurate.
- Specify the period for which you want to calculate MTBF. This could be, for example, the period from the beginning of the system's operation to the present, or a specific period for which you want to perform a reliability analysis.
- Sum up the times the system has operated without failures over a specified period. This can be the time between failures or the time from the beginning of the system's operation to the present minus the total downtime due to failures.
- Count the number of failures that occurred during a specified period.
- Calculate MTBF by dividing the sum of failure-free times by the number of failures that occurred during that period.
MTBF calculation example:
Let's assume we have a machine that has been operating for 1000 hours, and during that time it has had 4 failures that took a total of 200 hours to repair. The total failure-free operating time was 800 hours. We can calculate the MTBF using the formula: MTBF = 800 hours / 4 = 200 hours.
This means that the expected mean time between failures for this machine is 200 hours.
MTBF can be a useful tool for assessing machine reliability, but it is worth analyzing other indicators as well and taking a comprehensive approach to assessing machine reliability and availability depending on specific requirements and operating conditions.
