Authors - Ravi Chaudhary, Ashish Kumar, Monika Saini, Kapil Kumar Abstract - The prominent objective of present study is to conduct the behavioral analysis of single unit systems in classical and Bayesian setups. For this purpose, a stochastic model of single unit system is developed with the concepts of preventive maintenance, degradation, waiting time for repairman, single server, perfect switch devices, and Weibull densities. The degraded unit after failure replaced by new one. A simulation study in classical and Bayesian setup is carried out for behavior analysis of the system. Various measures of system effectiveness are derived in both frameworks using semi-Markovian approach and regenerative point technique. The numerical values of various measures of system derived to high light the importance of the study. The results may be beneficial for system designers and maintenance personnel.