In the context of Second Generation Intact Stability Criteria (SGISC), a need for a comprehensive analysis among the different stability failures has been identified, to improve a balanced final design result in terms of ship stability performance. In this paper, the first vulnerability level criteria are analysed and a system approach (Design Structure Matrix) has been employed to observe comprehensively all stability failures. SGISC criteria have been applied to a set of Megayacht unit parent hulls and results are analysed in order to quantify the effect of some specific parameters on the whole ship stability performance at once.