The current developments in the world result in increasing tensions between different countries. This increasing tension requires materials that are available when needed. Major budget cuts have resulted in the disposal of six multipurpose frigates which has reduced the total amount of frigates owned by the Royal Netherlands Navy from twelve to six. Because of this significant reduction, a high availability of the remaining frigates and oceangoing patrol vessels is required. However, the availability of these vessels is not sufficient at the moment. In this research a suitable definition for the term 'availability' was found in the term 'operational availability' which is a function of the maintenance process. With this definition the operational availability of the multipurpose frigates, air defence and command frigates and oceangoing patrol vessels was calculated. The calculation showed that the operational availability of these ships does not meet the operational availability requirements. The maintenance process was analysed by using the Delft Systems Approach to determine the problems that cause the low operational availability of the ships. The analysis showed a significant amount of problems that influence the operational availability of the ships in a negative way. This study developed a continual process improvement dashboard that can be used by the Royal Netherlands Navy as a tool to improve the operational availability of their existing ships. Besides that, the dashboard can also be used in the design process of a new ship class to achieve the desired operational availability for the new ships.