The requirement was to provide a data entry and reporting application for sets of information (the definitions of which could change), potentially frequently and rapidly. In the past this usually required additional development or changes whenever new data was identified; metadata-driven applications were typically very restrictive and performed poorly.

We developed a flexible data structure in an SQL Server database for storing both the metadata which defines the details of the data to be collected, as well as the underlying value data. This is all stored in a fixed set of tables which represent the structure of the data; this structure may also be hierarchical in nature. An ASP.NET web front end allows both head-office system operation, and also field-based (Internet) data entry. Since the underlying business model is user-definable, the ASP.NET web front end is generated from the business meta-data for presentation to users. This is performed real-time, so that a change to the meta-data is instantly reflected in the front end.