This chapter provides an overview and account of the development of a conceptual framework: the Sports Policy factors Leading to International Sporting Success (SPLISS) model. Three research issues lay at the root of the SPLISS model; namely, theoretical, methodological and political issues. A theoretical issue appeared because of the lack of an empirically grounded, coherent theory on the factors determining international sporting success. The SPLISS model clusters all factors within sport policy that can contribute to success in policy dimensions, called Pillars, situated at two levels: inputs and throughputs. The chapter details the SPLISS design, with a specific focus on process. The SPLISS project used a three-phase exploratory sequential design: qualitative phase, mixed phase and follow-up phase. In a second phase of the SPLISS project, the conceptual framework was tested empirically in an international comparative pilot study with several nations.