Designing maritime safety management systems commonly follows basic processes which focus on fulfilling the demands of the regulations in the industry. This provokes designing systems with limited application which are not capable to efficiently use the guidance contained in regulatory demands, and more importantly, creating systems which are not capable of representing, evaluating, and improving the dynamic management of safety-critical organizations. This article proposes a safety system engineering process for designing maritime safety management systems which is based on the Systems-Theoretic Accident Modelling and Processes (STAMP). This process is applied for sketching the safety management of the Vessel Traffic Services in Finland. The aim is to systematically represent the function of the utilized controls for ensuring the internal VTS safety management and the safety of navigation in Finnish sea areas. The outcome of this study provides a descriptive process of analysis for designing maritime safety management systems. In this process, two other concrete elements are included for supporting the functioning of the safety management system to be designed. First, the adaptation of an identification process for determining key performance indicators for planning, monitoring and evaluating the functioning of the safety management system. Second, the constitution of a performance monitoring tool capable of executing the monitoring, measuring, and updating of the determined key performance indicators and the general functioning of the designed safety management system.