The theoretical foundations of accelerated life tests and their applications are systematized and described when solving problems of assessing and predicting the state of technical systems, the reliability of which is characterized by several "critical" components and resource consumption parameters at the same time. Justification of accelerated life tests of technical systems is carried out on the basis of a generalized approach to the selection of optimal values ​ ​ of the volume, modes and duration of tests, taking into account the main indicators and criteria that determine their effectiveness.