<p>This article explores the extension of the stress-strength reliability model of a system and the multi-component systems when the components of the system are considered to be non-identical. These components are separated into two categories. Each component of the system has some strength and the common random stress applied to it. The component strength of both the categories follows Power-Muth (PM) distribution and the stress applied to the components also follows PM distribution. It may follow any other lifetime distributions. Both the strength and the stress are independent of each other. The estimation of stress-strength reliability and multi-component stress-strength reliability is carried out using well-known ML and MPS estimation methods. Based on varying parameters, the reliability of the models is discussed. All the statistical calculations are done by using Monte Carlo simulation. Real data applicability of the extended model is also performed in the article.</p>