AERAS aims to develop a realistic and rapidly adjustable cyber range platform for systems and organisations in the critical healthcare sector, to effectively prepare stakeholders with different types of responsibility and levels of expertise in defending high-risk, critical cyber-systems and organizations against advanced, known and new cyberattacks, and reduce their security risks. The platform will be a virtual cyberwarfare solution enabling the simulation of the operation and effects of security controls and offering hands-on training on their development, assessment, use and management. The platform will be based on an evidence-based approach where virtual cyberwarfare and simulations are configured according to evidence regarding: (i) the occurrence of cyber threats, and (ii) the effectiveness of the operation of the internal and external system defence mechanisms. Evidence will be collected by multi- faceted real-time monitoring and assessed according to Cyber Range Security Assurance (CRSA) models specifying potential cyber-attacks, the security mechanisms used against them, and the methods for assessing their effectiveness. The AERAS solution will be delivered at TRL-7 and validated through two different pilots in the healthcare sector: (i) a hospital medical systems pilot; and (ii) a public health systems pilot.