The Analysis of System Reliability

Abstract

The ability of an engineering system or products completing the prescribed functions under the prescribed condition and within the prescribed time is called reliability. In the design stage, prescribed functions of an engineering system usually can be expressed as the function of input variable x, which usually can be called the state function g(X). The value of the state function can judge whether functions of an engineering system can meet the design requirements.The most common judging logic is two-valued logic. When the state function g (X) exceeds a certain status (a certain allowed value), an engineering system can't meet a function requirement prescribed as the design. The particular state is called the limit state of the function. If an engineering system can conform to functional requirements specified as the design, then the system can be judged as "reliable", conversely it can be judged as "invalid" or "unreliable". Usually, the reliability of an engineering system is divided as the zero point of a state function.Reliable: Invalid:Then the judging function of two-valued logic (also called the indicative function) can be written as: