The theme of lessons learned through projects is becoming increasingly prevalent, given its approach in institutions, and the growing production of academic research on the topic. Models for Management of Lessons Learned (GLA) have been developed, based on processes and tools such as social software (e.g. Wikis, Blogs and Microblogs). Considering the problem of disuse or lack of knowledge of processes and tools for GLA in institutions, this empirical research aims to validate a GLA model in a government public safety institution. The model was placed in a Wiki platform. This work uses the Design Science Research (DSR) paradigm and the method of Technical Action Research (TAR). The results suggests increases to the model placed in the list of processes of lessons learned by phase of life cycle of the Project, while the utility and facility in the use of Wiki were recognized by those involved, who also consider that there is a positive effect on the efficiency and efficacy in the processes and activities of the Project. The contribution to theory lies in the confirmation that investing in the adoption of techniques and tools in projects is essential, and that it is possible to innovate in Brazilian public safety through good project practices. The contribution to practice is presented in the adoption of a systematic model for GLA in new projects at that institution.