The article presents an approach aimed at automatically deriving the initial conceptual database model from a set of business process models. The approach proposes the incremental synthesis of the target model by iteratively composing the partial conceptual database models that are derived from the models contained in the source set. The approach is implemented by the AMADEOS tool, which is the first online web-based tool enabling the automatic derivation of the conceptual database model from a set of business process models. The experimental evaluation proves that the implemented approach enables effective automatic derivation of the initial conceptual database model.