ABSTRACT
The theory of reliability has been developed in order to ensure operability of technical objects (components and systems). However, no thorough explanation of the term “functional reliability” is given by now, although it is used with increasing frequency. We deduce a definition based on the terms property, quality and function. In this connection, we draw attention on the principal differences between functional and structural reliability. We explain similarities between functional safety and functional reliability and show how they smoothly change one into the other.
