Tag Archives: sample size

Thoughts on Testing One Sample and No Failures


14598506379_df6e4e22e0_zReliability Testing with Constraints

In some cases we have to conduct testing and are asked to not break the product. Now, that isn’t all that fun as a reliability engineer. We want to find what fails and understand it. Or, we want to confirm what we expect will fail, actually does as expected.

So, what do we do when confronted with a very small sample size (that is one issue) and are expected to conduct failure free testing (second issue)? Let’s explore each issue separately and come up with a few suggestions on how to proceed.

Thanks to Олег (@OlegV_Ivanov) via Twitter for the article suggestion. Thanks for the idea  Олеr. Continue reading Thoughts on Testing One Sample and No Failures

Sample size and MTBF

Samples for Testing

Normally, we life test a sample of products in order to make sure the products will last as long as expected. We assume that the sample we select will represent the total population of products that we eventually ship. It is not a perfect system, and there is some risk involved. Continue reading Sample size and MTBF