This thesis studies the notion of knowledge in business firms, and in particular the concept of knowledge mobilization, understood as the mechanisms used by organizations to apply, transfer and retain knowledge about cause and effect relationships. As a theoretical framework, we use here a derivative of the resource based view of the firm called the knowledge based view. This theory is used to understand and analyze how service organizations in international strategic alliances developed and refined their knowledge base.Methodologically, this thesis utilizes a qualitative, longitudinal perspective, based on several cases of organizations in similar structural context but whose results after a few years of operation show large variances. The findings of this work show that the usefulness of knowledge for business firm (its value), is highly dependent on the life-cycle of the organization. Also, the types of knowledge mobilized varied also according to position in the life-cycle. Whereas younger, inexperienced organizations sought to transfer and develop knowledge, older organizations tried to prevent knowledge from dissipating. All these findings contribute to the creation of a contingent, evolutionary view of knowledge in business firms. In addition, the notion of knowledge consolidation (or effortful activities needed to maintain a piece of knowledge in the organization) is developed, and evidence is presented to support it