In this paper, we present a method that integrates distributed data managed by a variety of DBMSs. We focus on an infrastructure designed to assist business modelling and requirements analysis. ERA method that describes the enterprise's structure provides metamodels which are stored in the SIS semantic repository. The infrastructure suggested uses the semantics of the database information which are acquired by the application of a database re-engineering method and depicted in a EER model. We explain the framework and we describe the structure of our approach and the mechanisms that accomplish the data integration