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June 22nd, 2016 17:00

# MTBF

In "Information Storage & Management v2 " book, there is question regarding calculating MTBF (mean time between failure) in Lesson 10 Backup and Archive. Can anyone please provide answer and brief solution to that question ? It is really confusing to me.

633 Posts

June 24th, 2016 12:00

Hi Alok,

This answer comes from SomuG :

AVAILABILITY

·        System needs to be operational from 8am to 5pm = 9 hrs per day and for 5 days it is 45 hrs

·        Non availability (Mon to Friday) (ie) any time of the day the system was not available during 8am to 5pm

o   Monday 8-11 = 3 hrs

o   Tuesday = 0 hr

o   Wednesday = 1 hrs (only 4PM to 5PM)

o   Thursday = 0 (since failure was outside operational hours)

o   Friday 1-2 = 1 hr

·        Total time not available for the operation= 3+0+1+0+1 = 5 hrs

·        Availability of the system = (45-5)/45*100 =  88.9%

MTBF (MEAN TIME BETWEEN FAILURE)

·        Total up time / number of breakdowns that affected the up time (ie) during operational time (8am-5pm)

·        =40/3 = 13.33 hrs

MTTR (MEAN TIME TO REPAIR)

·        Total down time / number of breakdowns during operational time

·        5/3 = 1.67hr

633 Posts

June 23rd, 2016 05:00

Hi Alok,

Can you share the question specifically?

28 Posts

June 23rd, 2016 11:00

633 Posts

June 23rd, 2016 12:00

Alok, I'm looking at my copy of the ISM v2 book, and I don't see that question anywhere. What page is it on?

28 Posts

June 23rd, 2016 15:00

HI Kate,

it's on page no 222, question no .2. In that question, they have asked for availability of component 2 only. But for my better understanding, please show me the calculation for  MTBF and MTTR too.

28 Posts

June 24th, 2016 13:00

Hi Kate,

7 Posts

August 30th, 2020 03:00

Sir,

We have supplied 1 R630 and 4  R730 to our client BSNL .

Customer want to know documenration/calculation for MTBF/MTTR

Will you pl. guide

Community Manager

•

478 Posts

August 31st, 2020 05:00

Hello bhupendrachaudhari,

https://www.dell.com/community/PowerEdge-Hardware-General/Re-Mean-Time-Between-Failure/m-p/7682460#M65899