Resilient control approaches can be applied in any cyber-physical system that utilizes distributed communication and control architectures that provide automation support to enable human operators to better run systems. Power systems operations utilize a decentralized control scheme with human operators playing a critical role. The control of the power system takes place over a range of time scales. Operators largely respond to slowly changing conditions with time scales ranging from tens of minutes to hours, with support from computer simulation and automation tools. Many utilities maintain multiple communication systems which overlay the power system. The utility control center often forms several bridges between the enterprise system and the utility uses for financial operations, such as retrieving information for billing from the operational network. Cyber security is becoming an increasing concern for power systems operations. The power system operator teams have opportunities to invest in cyber defenses.