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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From your second example attached above, what I understand is that using constant time windown to calculate MTBF will give higher values if there are improvements made during that constant time window. Josh, The moving time window is just a convention or a rule to set the time span within which performance indicators PI are to be calculated. Do you know which English references discuss this matter at length? Membership Required We’re sorry. This inaccuracy can lead to bad design decisions.

If the MTBF mttd 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. Seems there’s acronyms for every icon and it’s growing.

MTBF value prediction is an important element in the development of products.

To go back to my question, what would be your calculated mtbf for the Rui’s example above? What if there are no failures, then the denominator for frequency of failures is zero which gives an MTBF of infinity.

The most important result from all this was that Mbf could plan long runs and we could schedule our maintenance to suite. Using similar logic, MDT for a system out of two serial components can be calculated as: It has to go beyond compiling data to get an attaboy. The most significant was that most of the pumps had grease lubricated, gear couplings.


This includes notification time, diagnostic time, fix time, wait time cool downreassembly, alignment, calibration, test time, back to production, etc. I looked back over the failures and identified several key failures that kept repeating across the group. First of all, let’s note that the probability of a system failing within a certain timeframe is the inverse of its MTBF.

Note that it must be done on equal equipment in de same operating conditions. Then, when considering series of components, failure of any component leads to the failure of the whole system, so assuming that failure probabilities are small, which is usually the case probability of the failure of the whole system mbtf a given interval can be approximated as a sum of failure probabilities of the components.

Like Reply 0 Likes. We will have a large number of repairs that are quick to repair, and a small number that take much longer.

I saw your calculations and I would agree with them if I mtte not aware of the fact that you are simply trying to get rid of the time window constraint! I always follow the practices that I think are the best to a specific case whenever I implement a management performance control system and never accept an indicator calculated in a way imposed by some norm whose logic or justification I don’t agree with.

Cheddar Good job for increasing the mtbv for your refinery pumps. To do this, the indicator has to be built on data collected for a while in the recent past — typically a time window whose length has to be adjusted now and then in order to compromise stability the property of not going up and down suddenly and responsiveness the property of following the latest trend closely.


To take this discussion to the extreme, valcul ALL your equipment was only ever on stand-by, your MTBF would be calcu, they’d never fail!

Mean time to repair maintenance

One technician performs all tasks sequentially. In the case of MTTR, the effort should be exactly the opposite: Why do you we need to apply weightage to the data set for equipment under process of change?

To limit the impact of mean time to repair, organizations have their own maintenance teams, hold spare parts onsite or run parallel production lines. Stop wasting money for lack of data to make decisions based on IT or business indicators. I expect 7 yrs service and will accept 5 and iffen you can’t dalcul it plan on traveling and calcjl new people.

To get the optimum stability and responsiveness, how do I select the constant time window to calculate the MTBF? Above, we have the average time of each downtime.

MTBF & MTTR | What are they and what are their differences?

Forget not the effect of contaminants, cxlcul, etc, etc. Our “standby” units were invariably steam-turbine driven, auto cut-in units so that, in the event of a power failure, we could falcul running and these need to be just as reliable as the main units. Fundamentals of Electronic Systems Design. How to strike a balance? We want to help your company Stop wasting money for lack of data to make decisions based on IT or business indicators.

The MTBF of the system is the average of the three failure times, which is