The need to have a separate database in order to support the decision process was first recognized at the beginning of the 1970s (Sprague and Watson, 1996). Although the term "data warehouse" was not coined until the late 1980s by Bill Inmon, by 1985 big companies of telecommunications and banks began to build systems whose function was to provide managers with horizontal and global information on the organization (Watson et al., 1992). These systems were named EIS (Executive Information Systems) and constitute one of main precursors of data warehouses. The main purpose of the EIS was to support managers in learning about the organization, including the study of the main processes and the interactions with the exterior. It is demonstrated that its use enhances the decision process, providing an improvement in the managerial results. (Vandenbosch and Huff, 1992).