This book provides an introduction to the statistical analysis of observational and measurement data in reliability experiments and is primarily intended as a handbook for practitioners. Readers with a technical background who seek a deeper insight into mathematical statistics will find guidance in this book on how to handle empirical information and its connection to statistical methods. Compared to other applications of mathematical statistics, failure data have some peculiarities: they are time-dependent, which is reflected in the failure rate. The probability that all objects will fail during the observation period is low, resulting in censored samples. The probability of failure in the experiment can be increased by overloading, but one must also extrapolate the reliability under normal load conditions.