The Aegis combat system has been widely considered as one of the most powerful weapon systems for surface ships due to its high level of war-fighting capability. In 2009, Republic of Korea (ROK) Navy became the fifth country in the world that operates Aegis combat system-equipped ships through the KDX-III program, and a total of three Sejong the Great class DDGs (Destroyers with Guided missile) are currently in fleet operations. These ships have performed an excellent level of war-fighting capabilities such as successful tracking missions for the missile provocations by North Korea and ROKS Sejong the Great's top-gun award-winning at the firing competition during multi-national exercise. These are empirical supports showing outperformance of ROK Navy's DDGs in spite of its relatively short period of operations as less than six years when compared to other countries operating similar Aegisequipped ships. In this paper, we introduce ROK Navy's strategy, plan and efforts to realize these accomplishments in the KDX-III program, mainly focusing on how ROK Navy accomplished and settled a high level of war-fighting readiness in such a short period from the ship's training and familiarization perspectives. Primarily, ship crew's individual capability and team work as an entire ship force were considered as the fundamental for proper operation and maintenance, which precede the state-of-the-art hardware such as system and weapons. We introduce ROK Navy's systematic approach applied to training and familiarization as a core factor to maximize ship's performance and readiness in this paper. From the beginning of the KDX-III program, a phased approach for ship crew was applied to develop skills from the basic to advance. Based on the programmatic foundation, we present plans and achievements by ROK Navy Headquarters and fleet operations, which provided various opportunities including on-board familiarization and utilization of the Aegis Operation and Maintenance Center (AOMTC) – ROK Navy's own education and training facility for DDGs. At the end, we conclude with lessons learned and proposals to utilize these efforts for force improvements in the future.