Embedded systems1 are increasingly deployed in critical applications, where reliability and availability are paramount to ensuring operational continuity and safety. Predicting these parameters accurately requires a comprehensive understanding of how environmental factors impact system performance. This paper explores an innovative approach to reliability and availability prediction by integrating environment modeling2 and simulation techniques. The proposed methodology captures the dynamic interplay between embedded systems and their operating environments, enabling precise estimation of failure probabilities and system downtime under varying conditions. The core of this study lies in developing a multi-faceted simulation framework that incorporates environmental stressors such as temperature3, humidity, vibration, and electromagnetic interference4. The framework models these stressors in real time5, using historical and simulated data to evaluate their cumulative effects on the embedded system's components. By coupling these models with system-level fault injection and degradation analysis, the proposed method facilitates the identification of vulnerabilities and critical failure modes. These insights are crucial for implementing targeted mitigation strategies, such as hardware redundancy6 or software fault-tolerance7 mechanisms, to improve system robustness. The findings demonstrate that environment-aware modeling significantly enhances the accuracy of reliability and availability predictions compared to traditional approaches that overlook external influences. The paper highlights case studies involving automotive and aerospace applications, showcasing how the framework reduces design-cycle time and supports decision-making in system design and maintenance planning. By bridging the gap between environmental simulation and system reliability assessment, this work provides a scalable and practical solution to predict and optimize the long-term performance of embedded systems in diverse operating conditions.