<p>The paper deals with stochastic analysis of a complex system composed of two sub-system A and B connected in series configuration. The subsystem A consists of k identical components in series network where as subsystem B contains of n identical components in parallel network. The failure rate of each component arranged in series and parallel network are taken to be constant but they are different in each case of subsystem A and B. The supplementary variable technique is used to find out various measures of system effectiveness. The feasibility of the proposed system model has been analyzed in the context of an industrial robot control system with redundant sensors and actuators. Classical and Bayesian estimation also considered to find out the estimates of unknown parameter for MTSF and steady-state availability in particular case. From the sensitivity analysis of reliability it is concluded that failure rate of subsystem A is more sensitive than failure rate of subsystem B. Moreover, from the estimation method it is revealed that the estimated values of MTSF and steady-state availability are closer to the true values.</p>