Supervisory control and data acquisition (SCADA) systems are commonly used in the offshore oil and gas industry for remote monitoring and control of offshore platforms. Using a generalized platform system architecture, the reliability of the entire system is estimated. The outcome of this reliability assessment is an estimate of mean time between failures (MTBF), system availability, and probability of facility damage or pollution release. The reliability was estimated using probabilistic risk assessment. A fault tree was constructed to show the effect of contributing events on system-level reliability. Probabilistic methods provide a unifying method to assess physical faults, contributing effects, human actions, and other events having a high degree of uncertainty. The probability of various end events, both acceptable and unacceptable, is calculated from the probabilities of the basic initiating failure events.