1. A computer program product, tangibly embodied in an information carrier, the computer program product comprising instructions operable to cause data processing apparatus to: receive a specification of a model comprising multiple model classes, each model class having one or more model class properties and one or more relationships to other model classes; and generate a storage area structure based on the specification of the model, the storage area structure comprising: multiple nodes, each node corresponding to a model class; multiple attributes, each attribute corresponding to a model class property; and relationships between the nodes and attributes based on the relationships between the model classes.