Re: Validate 99.5% reliability 90% confidence - Sample size calculation
Someone has stated if the test is performed using the 95th percentile usage profile (more harsh usage profile than the median user), then I can validate the same reliability using a smaller sample size.
I never heard of 95th percentile usage profile and don't know what is meant by that. It doesn't sound right to me. The word harsher sugests you are referring to some accelaration factor. Other than temperature which can be used as an acceleration factor and for which the relationships are known I don't know of any acceleration factor that can be used readily.
Assuming that you are referring to accelerated testing, the test time can be reduced or conversely the sample size if the test time remains unchanged. I wouldn't take that formula as correct unless you have the full reference how is it derived. ooks suspicious to me