Outsourcing has been growing as a mode of business in Brazil over the past decade. Initially concentrated in information technology functions, it soon expanded to the telecommunications industry following the privatization of telephony operators in 1998. However, in spite of the major business that have been closed over the past 4 years, and the fact that their implementation continues to be considered a complex, high-risk operation, there are indicators pointing to a strong trend towards growth in this activity over the next few years in Brazil. The insertion of outsourcing in a strategic context in which it is treated as a kind of strategic alliance would therefore seek not only better results concerning its implementation, but also the construction of sustainable competitive edges for both of the parties concerned.The main purposes of this thesis was to develop an analytical framework that can help companies operating in Brazil effectively outsource critical functions. Therefore, the research started from the development of its theoretical basis, which sought to address the definition of the outsourcing concept, the implications of its implementation, and its categorization as a kind of strategic alliance. Upon introduction of the theoretical basis, an outsourcing typology was proposed which, together with the selected research methods, served as a basis for the subsequent stages of the thesis.In conclusion, a framework was proposed in a step-by-step structure to assist in the outsourcing of critical functions, inserting it into a strategic context so as to allow sustainable competitive edges to be sought. A new study case was presented, this time for the purpose to preliminarily evaluate the possibility of using the framework in an actual outsourcing case within a strategic context. The results obtained from this evolution and supported by the activities that were previously conducted allowed this thesis to contribute to both the academic area and the managerial practice, treating outsourcing firstly as a means to form strategic alliances, and providing the managerial practice with a framework to guide its implementation in such a manner as to get better results and seek to develop sustainable competitive edges.