# A Study on Identification of Development Status of MASS Technologies and Directions of Improvement
## 6 Conclusions
High data rates, real-time communication, and integrity of data should be taken into consideration with the resilience of data transfer and robustness for the development of the communication system for efficient communication between an autonomous ship and the SCC, the ship and satellites, the ship and other manned/unmanned ships, and even the ship and multiple vehicles such as AUVs, USVs, UAVs for the data acquisition of environment data. In addition, as malicious activities grow and new technologies emerge, new security challenges will materialize, and the suitable protection of systems, networks, and data in cyberspace will be required as an integral part of a safety system. Fifthly, issues for maintenance and repair of the autonomous ship have been identified with items to be considered. As there will be no seafarers onboard for maintenance and repair, preventative measures are essential to improve reliability in terms of hardware and software functions, solve functional problems through remote diagnosis and selection of applicable and effective tasks, and develop a system to make a ship return to a port as a last measure when the ship cannot function or operate appropriately anymore. To ensure the reliability of systems and equipment, both RCM, including CBM and Risk-CM, should be considered to find an appropriate solution for maintenance, with a strategy of redundancy and diagnostics and/or prognosis. Furthermore, a more detailed elicitation of experts will be beneficial to resolve black swan issues pertaining to hazards threatening the safe and efficient operations of autonomous ships and evaluate the actual feasibility of the mitigation measures. Lastly, hazard analysis of the autonomous ship has been explored in the paper. The autonomous operation has both positive and negative influences on the safety of the vessel, and it is needed to identify reduced/increased hazards to ensure the efficient and safe operation of autonomous ships. However, traditional hazard analysis methods developed several decades ago may not be suitable to analyze hazards of modern, complex, and software-intensive autonomous systems, so relatively new methods need to be developed and applied to analyze the hazards of autonomous ships. STPA and FRAM are identified as the most representative new methods that can be used for hazard analysis of autonomous ships, and we could also find several studies that have applied other new methods, such as SysML, OPM, BBN, and HFACS. While each study suggested a different hazard analysis method, they commonly argued that traditional methods are not sufficient to ensure the safety of autonomous ships. Further studies should be carried out, and guidelines need to be developed to identify optimal hazard analysis method(s) for autonomous ships. In this study, trends of major research areas for the realization of MASSs are identified. The six areas mentioned above will require continuous and detailed studies. In addition, for the actual operation of the MASS, studies on the definitions of seafarer and remote operator must be carried out promptly, and studies that have been focused on MASS degrees 1 and 2 so far need to be extended to future research considering degrees 3 and 4. C.-J.C.: overall structure, conceptualization, and chpater 1, 2, 3 and conclusions; M.K. : conceptualization, review and chapter 4; H.-J.K.: review and chapter 5. All authors have read and agreed to the published version of the manuscript. This research received no external funding. The authors declare no conflict of interest.