Industrial products with high customer performance need the profound specification of the physical reliability. Application of conventional statistics result in long, extensive and expensive testing techniques, when failure rates of technical components or system parts are in the range of few ppm. A second reason for the application of the physical reliability concept is the replacement of the common "black-box-analysis" by the genuine identification and investigation of weak parts of a construction. Lifetime of technical systems or construction elements depends on the specific material behaviour, the mechanical-thermal-chemical load and on the environmental conditions during operating time. The work done in ICR is focused on the investigation of the physical reliability of materials, composites and technical systems used in microelectronics as well as in material science. Only the combination of theoretical aspects, focused experimental investigation and mathematical modelling can yield quantitative results to describe the reliability of considered items.