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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MTTR and MTBF, what are they and what are their differences?

If the MTBF has increased after a preventive maintenance process, this indicates a clear improvement in the quality of your processes and, probably, in your final product, which will bring greater credibility to your brand and trust in your products. What do you mean by moving constant time window? Even if it’s only a calccul of years, it’s a good starting point.

Have you got any questions on these two indicators? It doesn’t mean that you would not cases with a more extensive life: If not roll up your sleeves and get to work: From Wikipedia, the free encyclopedia. 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.

Also caocul time between Failures, not between the start point and end point. But the trend cannot be built on a long period; otherwise management won’t get response but too much stability instead and it will calcu, too late when he finally notices an undesirable trend. Using similar logic, MDT for calcull system out of two serial components can be calculated as: In such cases the mean time between failure refer to the average time of breakdown until the device is beyond repairs.

That is the principal reason why so many bearings which should fail from fatigue keep going well beyond mrtr life estimate: Also your paycheck should increase. I mthr back over the failures and identified several key failures that kept repeating across the group. I think you said that my approach of calculating the MTBF based on the longest time window gives stability but not responsiveness. For each observation, the “down time” is the instantaneous time it went down, which is after mytr.


The failure rate is the reciprocal of this and is 0. One more question, did you track the mtbf of the pump components individually such as bearings, seals, impellers, etc? At the same time I introduced a vibration monitoring programme along with lube oil analysis and thermography.

Mean time between failures – Wikipedia

Rotors are generally rugged and up to the task as is the shaft and other components. The MTBF of the resulting two-component network with repairable components can be computed according to the following formulae, assuming that the MTBF of both individual components is known: 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.

Another was poor alignment and there were many premature bearing failures. Such nomenclature is used when it is desirable to differentiate among types of failures, such as critical and non-critical failures. This is to say that I don’t follow norms in what “management performance control systems” are concerned but I, of course, accept to consider any when a client points me out in that direction with the condition that I freely decide whether to advise and justify its adoption or not.

I’m looking at MTBF of a machine and a group of similar machines. You must be signed in to continue.

Formula for MTBF | AMP Maintenance Forums

The method can be easily implemented in software and the indicators made available on a timely basis.

In case where we achieve perfect MTBF of hours a month, then we assume a denominator of one, since anything you divide by 1 will give you the numerator. Taking too long to repair equipment can mean product scrapmissed orders and soured business relationships. Views Read Edit View history. Further, how do I select the appropriate weightage to be applied to the recent data? This page was last edited on 6 Decemberat By doing this, you attribute more importance weight to more recent events and less importance weight to older ones.


Over the lifetime of an asset, each failure will vary depending on the severity of the issue. Generally the weakest link is the equipments bearing. Yes, Cheddar, that’s what I think but somebody said the second formula above should be used because we cannot find the exact start and end dates.

How to strike a balance? However, I would like to follow a standard method to calculate the mtbf so that I can compare my figures with published mtbf data such as those for HP Bloch’s book. MTBF will also indicate the effectiveness of your maintenance practices and also any steps you might take to improve reliability.

Needless to say, there was no war between Operations and Maintenance in this refinery Rolly! The most important result from all this was that Operations could plan long runs and we could schedule our maintenance to suite. Differentiating these concepts is essential for businesses of all sectors, especially those working with high-availability environments where failures can result in large losses with sales forgone or with loss of confidence in the delivery of services.

I took a long time and looked at the pump failures just for the previous five years, and came up with the 6 months.

Go back to the beginning of your reliable breakdown data. The weighed data methods that I wrote about in my previous posts on this thread offer a way of calcuk the best possible trend awareness.