Journal of Digital Information Management Marius Octavian Olaru, Maurizio Vincini 12 4 2014 http://dline.info/fpaper/jdim/v12i4/4.pdf Collaborative business making is emerging as a possible solution for the difficulties that Small and Medium Enterprises (SMEs) are having in the current difficult economic scenarios. Collaboration, as opposed to competition, provides a competitive advantage to companies and organizations that operate in a joint business structure. When dealing with multiple organizations, managers must access unified strategic information obtained from the knowledge repositories of each individual organization; unfortunately, traditional Business Intelligence (BI) tools are not designed with the aim of collaboration so the task becomes difficult from a managerial, organizational and technological point of view. To deal with this shortcoming, we provide an integration, mapping-based, methodology for heterogeneous Data Warehouses that aims at facilitating business stakeholders access to unified strategic information obtained from a network of heterogeneous collaborating SMEs. A complete formalization, based on graph theory and the RELEVANT clustering approach is provided together with experimental evaluation of the proposed methodology over real DW instances.