This preprint presents a Theory of Data for non-transactional information systems, developed from the conceptual and formal foundations of the G Model.
The proposal distinguishes between Fact, Act, Document and Data, and defines the document as the computerized representation of an act. It formalizes the transition from variable components in an open document to immutable historical data in a closed document, together with the role of references, connections, states, roles and rules.
The work proposes an information-centric framework in which system behaviour is determined by the nature and relationships of information rather than by predefined transactional procedures.