Many of today's critical infrastructures, including Industrial Control Systems (ICSs), are evolving with the integration of numerous connected cyber components with legacy systems. This evolution has exposed ICS to a wide range of security vulnerabilities, requiring different cybersecurity considerations. Understanding how severely cyberattacks can exploit such system vulnerabilities to disrupt or delay system operations is paramount for developing targeted and effective defenses. In this thesis, we present a four-stage impact analysis approach to observe and characterize the manifold impact of cyberattacks on ICS operations. Representative tampering and spoofing attacks demonstrated on a timed automata model of a manufacturing cell control system show how classical and statistical model checking, respectively, are effective at identifying and quantifying the severity of cyberattack impact on ICS mission objectives. Furthermore, the impact analysis results provide extensive insight into the varying impact caused by different attackers and how systems with defenses can mitigate such impacts.