The document presents a stochastic model using stochastic reward nets (SRNs) to analyze the performance and quality of service (QoS) in IaaS cloud computing systems, addressing the complexity of integrating management strategies and user needs. It outlines the limitations of existing methods like simulations and on-the-field experiments and introduces a scalable and flexible approach to evaluate metrics such as utilization, availability, and responsiveness. The proposed system allows for a comprehensive evaluation of resource management strategies while considering system elasticity, thus aiding managers in optimizing cloud performance.