This paper presents a case study of use of CMMI (Capability Maturity Model Integration) best practices for an organization that want to improve their software development processes. The purpose was to improve the process area Requirements Management (REQM), supporting the level of compliance with the Verification (VER) and Validation (VAL) process areas. IDEAL (Initiating, Diagnosing, Establishing, Acting Learning) was used to implement best practices. SCAMPI (Standard CMMI Appraisal Method for Process Improvement) was applied to evaluate the current status of the institution's processes. The results show that the management of the requirements was improved, defects were reduced, and customer satisfaction was achieved.