Mission Impact Assessment (MIA) is a critical endeavor for evaluating the performance of mission systems, encompassing intricate elements such as assets, services, tasks, vulnerability, attacks, and defenses. This study introduces an innovative MIA framework that transcends existing methodologies by intricately modeling the interdependencies among these components. Additionally, we integrate hypergame theory to address the strategic dynamics of attack-defense interactions. To illustrate its practicality, we apply the framework to an Internet-of-Things (IoT)-based mission system tailored for accurate, time-sensitive object detection. Rigorous simulation experiments affirm the framework s robustness across a spectrum of scenarios. Our results prove that the developed MIA framework shows a sufficiently high inference accuracy (e.g., 80 \%) even with a small portion of the training dataset (e.g., 20–50 \%).