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Life expectancy calculation

Life expectancy calculation

Life expectancy calculation

(OP)
I work for a cement company and my project is to basically predict when several pieces of equipment are going to fail for cost estimate etc.  I have a lot of historical data and frequency of work done on each piece of equipment but no "normal life expectancy" but do have this particular plant's life expectancy.  How do I calculate a "normal life expectancy" and how would I tie the difference between the "normal life expectancy" and the plant's expected life expectancy into a final calculation for a prediction on when I should replace these specific pieces of equipment?a

RE: Life expectancy calculation

In cases where I have actual plant data for my own plant, I typically opt to use my own plant data. It accounts for the real life experiences my equipment will face. For my equipment, this is the "normal life expectancy".

If I am using someone else's data (eg from a book, survey, etc), I am basically hoping that their actual conditions is approximately the same as mine. Which is rarely the case.

For example, on a valve failure, calculating MTBF. I would much rather use actual plant data, than those published in books.

"Do not worry about your problems with mathematics, I assure you mine are far greater."   
Albert Einstein
Have you read FAQ731-376 to make the best use of Eng-Tips Forums?

RE: Life expectancy calculation

Cement company, lots of dust, lots of persons, lots of headache...
The L10 theory of bearings works under laboratory conditions, in real life they use a 4 lbs "persuader" to mount it.

RE: Life expectancy calculation


i agree to Ashereng..for me books is definitely used as a guide. It is better to rely on the actual plant data.

Actually, life expectancy is hard to comply when you clashed with the Operations Department as Top Management Level interferes for schedule, schedule..profit..profit..profit, blah, blah.. you what i mean!

Better planning means Sucess!

RE: Life expectancy calculation

By the way is there a reliability foum over here to discuss these things?

RE: Life expectancy calculation

Don't think so. You should start one.

"Do not worry about your problems with mathematics, I assure you mine are far greater."   
Albert Einstein
Have you read FAQ731-376 to make the best use of Eng-Tips Forums?

RE: Life expectancy calculation

There is indeed a forum for reliability:forum961

However, you may want to do a websearch on "AMSAA Crow" to find references on creating reliability plots and predictions based on actual data, such as:
http://www.barringer1.com/nov02prb.htm

TTFN



RE: Life expectancy calculation


While on the subject, I was trying in vain to find a complete list of forums on eng-tips, but in vain. How can I know all the stuff the I must be missing out on?

The links, including the "View All" ones, take me to some page that lists "only the first few headings" leaving the rest to imagination.

Any leads, please?

RE: Life expectancy calculation

Thank you, IRstuff.

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