To reach the "correct" ruling (the sturdy house) so that a person knows exactly what their rights and responsibilities are before God.
For a deeper dive into this academic discipline, you can find the complete text of "Fıkıh Usulünün Mahiyeti ve Gayesi" published by the İSAM (Center for Islamic Studies) . USUL AL-FIQH: ITS EPISTEMOLOGY, PURPOSE, AND USE FД±kД±h UsulГјnГјn Mahiyeti Ve Gayesi
Like a master's blueprint, it is the methodology and set of tools (logic, language rules, and historical context) used to understand the divine texts. To reach the "correct" ruling (the sturdy house)