MTBF and Mean Life

[Frank]

I am a student and i don't have much experiences with the Weibull tool. I have to do a MTBF-Analysis with the Weibull-tool. I have suspended data with about 250 machines, but only 12 failed.

To get the MTBF , is it possible to use the Mean Life function in the Quick Calculation Pad in Weibull++ 6? Is the Mean Life value the same as MTBF??

[mosch]

You can use the Weibull++6 get the MTBF at a confidence level.

[surajkamath]

hi Frank

yes you can use Weibull++ or minitab to calculate the MTBF.

If you use weibull ++

Use the wizard.. This would help in filling the data step by step .


If you use Mintab

1 Put all the failure lives first in an excel column
2. identify the failures by 1 and suspensions by 0 in the adjacent corresponding cell in the immediate next column to the failure life data.
3. sort data according to failure life.
4 copy both columns in minitab and

Stat
Reliability/Survival
Parametric distrib / right censored
select column containing failure data in variables
click censor to select censoring column and suspended variable to identify the suspension in case 0 is identified as suspensions.
click ok and run as a weibull distribution

that will give ur the failure life as well as a mTBF

rgds

Suraj