Planning Life Tests

How many units should you test to confidently demonstrate your product's reliability? This is one of the most critical and cost-defining questions in product development. Testing too few items can lead to a lack of statistical confidence, while testing too many wastes valuable time, resources, and budget.

This article removes the guesswork by providing a clear, step-by-step guide to calculating the right sample size for your reliability life test. We will walk through the statistical methodology needed to design a test that is both efficient and statistically robust. Complete with a practical example and the necessary R code, this tutorial is essential for any engineer or manager looking to balance rigor with resources in their reliability program.