With increasing commercial space activities, design platforms are often used for repeatable space system design. One such platform is Valispace, which shows great promise as a more accessible and flexible tool. In this thesis a case study is performed on the project “Small Satellites for Gravitational Waves Observation” to compare project performance before and after implementation in Valispace. It was determined that Valispace increases design accuracy and allows for better risk mitigation. Time efficiency is lower during system setup, but better during the verification and sensitivity analysis phases. Verification is easier due to its communicative features and structured testing options. Strengths of Valispace include automatic change propagation, analysis generation, design flexibility and requirement centralization. Identified limitations are slow change propagation, limits to sensitivity analyses and some minor software bugs. Overall, Valispace increases project performance, with further recommended research on automation, templates and use in later stages.