This paper aims to analyze the extent to which the Superior Labor Court, through Precedent No. 331, violated the principle of tripartition of powers, by editing a rule regarding outsourcing, before the publication and enforcement of a specific law on the subject. For this, the research is based on the legal and doctrinal construction of the tripartition of powers of the Brazilian State, understanding its limits and delegations of competences related to the typical functions exercised by the Executive, Legislative and Judiciary Powers. In the sequence, there are motives for creating precedents in the Brazilian legal system, as instruments to standardize jurisprudence and guarantee equality in interpretation and enforcement. The competence of the Superior Labor Court for the issue of precedents is analyzed in order to determine the role exercised by the Supreme Court of Appeal 331 of the Superior Labor Court in the Brazilian legal scenario. There is no imbalance between the powers due to the publication of the summary under analysis, whereas, despite the tripartition of powers, they must act together, with the ultimate goal of the cohesion of the country's legal system. The bibliographical methodology was adopted in the research, by the material apparatus in doctrine and existing legislation on the subject. [ABSTRACT FROM AUTHOR]