Mean time between failures (MTBF) and mean time to repair (MTTR) are two very important indicators when it comes to availability of an. The MTTR formula computes the average time required to repair failed equipment and return it to normal operations. Learn how to calculate it with Fiix. 1, MTBF and MTTR Calculator. 2. 3, Month, February, 4, Name of Machine, M_3. 5, Operation availability (min/mo), 24, 6. 7, Frequence, 8. 9, MTBF.

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For further simplication, did you take the operating time period to start from the year of the refinery being built which isrgdless whether any pumps being replaced over the years?

Formula for MTBF | AMP Maintenance Forums

Remember that we are dealing with systems, facilities, equipment or processes that can be repaired. Mean time to repair maintenance. Rui What is the purpose of arbitrarily setting the time span and moving the time span forward as time goes by?

To take this discussion to the extreme, if ALL your equipment was only ever on stand-by, your MTBF would be “infinity”, they’d never fail! This way, the decision maker gets the best possible picture regarding the direction an indicator is taking and can act accordingly. Sitting in an office coming up with statistical data doesn’t do anything and I’ve never seen a computer pull a wrench although I have seen it done remotely.

To learn more about the availability calculation please read our article about the costs of a downtime.


Retrieved from ” https: In view of this, look like calculating the MTBF every month seems ok for trending purposes and comparing with the same industrial data published by others. Obviouslyif the equipment is used for a shorter period of time the probability of survival is higher.

MTTR Formula | Mean Time To Repair Calculation | Fiix

Yes, we could just take the straight forward approach that you used i. How long the system should work: Of course, many more indicators can be developed at the equipment level to reflect progress in the pursuit of objectives set by management. Once we pinpointed what particular machines with low MTBF we go on to what particular sub-assembly are always failing Level 4: A total of 4 failures occurred.

Machines mtbff like people, people are like snowflakes – no two alike. One wirebond machine my estimate will compose of aroundparts and most of them are electronic parts, this machine is full of boardsand one station can have around or more wirebonds. I bought a couple of oil baths and some heavy duty gloves. You see those pumps out there.

The failure rate is the reciprocal of this and is 0. In this example, only the latest 5 failure matter because the other 2 are already out of the time window, being consequently omitted or discarded.

Such nomenclature is used when it is desirable to differentiate among types of failures, such as critical and non-critical failures.

Suppose you are using a time interval of 6 weeks your calcjl window. This time I included an example of weighted values. First of all, let’s note that the probability of a system failing within a certain timeframe is the inverse of its MTBF. What is mean time to repair?


L10 rating is largely The result of all this hard work, and yes expense, was that after four years the MTBF was at a very healthy 37 months! I should simply have entered 1, hours straight in that cell. Forget not the effect of contaminants, lubrication, etc, etc. The MTBF of the system is the average of the three failure times, which is Note that a sudden move up or down in the last control period doesn’t mean necessarily that you are moving towards disaster nor heaven.

So the start time is where you start to actually compute your MTBF. Price Blog Contact us Become a partner Forum. How is mean time to repair calculated? Equipment manufacturers are now using a modular design philosophy so parts or sub assemblies can be swapped out quickly and easily.

How to strike a balance? Stephen Foskett, Pack Rat. To get the optimum stability and responsiveness, how do I select the constant time window to calculate the MTBF? Why not just calculate the mtbf since mtf first failure to today becasue you said the more the episode the higher the accuracy?

Do you calculate operating time by subtracting the running time before the first failure and running time after the last failure?