The chapter Pre-operation, Operation and Maintenance covers the essential phases to ensure the safe and efficient operation of offshore production facilities: pre-operation, which includes team formation and training, development of operational standards, maintenance process structuring, risk management, obtaining certifications, and equipment commissioning, preparing the facility to start production; and operation and maintenance, which involves monitoring safe operations, treating anomalies, managing maintenance and operational integrity, responding to emergencies, managing changes, conducting operations, and continuously evaluating management, integrating safety practices, preventive maintenance, change control, and performance analysis to ensure reliability, efficiency, and sustainability throughout the facility’s lifecycle.