MTTF Prediction for Customer Requirements - Parts-count MTTF prediction for the part

[Manix]

Hi all,

I have reviewed other threads and I am still totally confused by some customer requirements that I have received.

They have asked for the following:

"A Parts-count MTTF prediction for the part shall be made. Preferably, real reliability data for the actual components shall be used in the prediction."

That is about the sum of it! I have no idea where to begin in obtaining or presenting that data. This is an Automotive and I am going to be honest and confess I have never come across or had to submit this before and so I have no idea where to begin. To be honest, I am not even sure exactly what I should ask the customer if anything at all?

I do know that MTTF is "Mean Time to Failure" and that the figure should be greater than 50,000,000 hours!

Can anyone provide clarity, as I say I am a total Newbie to this kind of measurement/prediction.

Thanks,

[Tim Folkerts]

Welcome Manix,

"Parts Count" basically just means that you count how many parts you have of each type and estimate the reliability of each type of part. Then you calculate the overall reliabilty based on the combination of the parts. The method generally assumes no interaction between parts and that a failure of any one part will lead to a failure of the system.

Here is a site with a brief introduction to the topic and lots of good info about reliability engineering.

http://www.weibull.com/hotwire/issue51/hottopics51.htm



Tim F

P.S. I just noticed that while you may be new to reliabilty, you are not new to the Cove, so the "welcome" is a little out of place.

[Al Rosen]

Originally Posted by Manix

Hi all,

I have reviewed other threads and I am still totally confused by some customer requirements that I have received.

They have asked for the following:



That is about the sum of it! I have no idea where to begin in obtaining or presenting that data. This is an Automotive and I am going to be honest and confess I have never come across or had to submit this before and so I have no idea where to begin. To be honest, I am not even sure exactly what I should ask the customer if anything at all?

I do know that MTTF is "Mean Time to Failure" and that the figure should be greater than 50,000,000 hours!

Can anyone provide clarity, as I say I am a total Newbie to this kind of measurement/prediction.

Thanks,

You may want to look at Reliability Prediction Analysis and the attached.