In this article a method of assessment the software reliability is proposed. This method bases on the allocation of functional units - structured sets of logically related commands to ensure the implementation of a well-defined range of the one character's tasks. The reliability of the program consists of the aggregate achievements of the reliability of each functional unit,which has its own special set of possible faults and failures. Unlike most of the existing models for assessment the software reliability assessment in this method does not occur in the testing phase of software product but the final result evaluated.

Keywords: reliability software, reliability assessment, software, method for assessing the reliability, functional approach, functional unit, failure, failure of the program

Adaptation of the basic system principles (integrity, a necessary variety, flexibility, external addition and commitment) to quality management of the software is offered. The author proves useful effect from their application by means of detection of the features following from interrelation between the making elements of programs. Moreover such features can define new ways of software quality management.

Keywords: software quality, software, assessment of software quality, system approach, system principles, software quality management