This study seeks to find expressions for the reliability for a series–parallel system of ‘m’ subsystems with Weibull failure rules, each of which has ‘n’ non-identical components. These measurements’ expressions are found for the same constituents. The reliability values of the system have been assessed for random amounts of component count, component operating time, and failure rate. The reliability behavior has been observed for components with a monotonic failure nature by examining particular instances of Weibull failure laws. In order to increase the effectiveness of the study, the reliability trend for the system, which consists of subsystems with five components under various running times and failure rates, has been observed both numerically and graphically. In this paper, employs  Weibull distribution and mathematically models, to evaluate  the reliability of  series–parallel system.