This chapter describes the current status of expertise development in nuclear power production and oil & gas facilities, for both routine operations and emergency response. These are two examples of industries characterized by continuous operation, high hazard, and complexity, where operators must have the capability to monitor systems and respond to potential threats. Both industries rely heavily on written procedures and procedural compliance, along with an awareness that unanticipated and often unprecedented events can emerge. Emergencies in these industries are extremely rare yet on-site operators must be able to make the shift from their routine operational role to responding to escalating situations. Directed training is frequently used to enhance operator expertise in the absence of actual experience, with simulator-based exercises increasingly being introduced. The chapter summarizes existing research into the content and format of the skills required by operators in these settings and highlights potential areas for future investigation.