1. A method comprising: converting logical aspects comprising entity-relationship (ER) libraries, the ER libraries comprising ER models, the corresponding design items comprising design libraries and the design libraries comprising design models, of a common warehouse model (CWM) to corresponding design items for a relational database by: (a) scanning through the ER libraries; (b) for a first of the ER libraries, creating a corresponding first design library; (c) for each of the ER models in the first ER library, creating a corresponding design model in the corresponding first design library to hold corresponding information; (d) processing in a hierarchical manner each of the ER models to produce corresponding information for the corresponding design model; (e) determining whether there are any references between the ER models; and (f) whether there are any references between the ER models, specifying corresponding references in corresponding design models.