This study presents the report about a case study on the application of REACT (Requirements Evolution in Agile ContexT), an agile method to support software requirements development, in a real software development environment. This case study assessed the strengths, weaknesses, opportunities, and threats related to the assets that make up REACT, namely: work products, life cycle, roles, and ceremonies. About the results, it was observed that REACT was effective, simple to use, strongly collaborative, suitable, user centered and goal oriented. Thus, achieved its main purpose to evolve the requirements of a software product in iteratively, efficiently and under of the agile mindset. The results contribute to the software industry by providing empirical data about the use of a agile method to software requirements development, which can serve as a reference for organizations seeking the adoption of agile methods related to the requirements area, as well as to provide the scientific community with a better empirical understanding of the relationship between requirements and agile methods.